since the october 7th terror attack in israel there has been a spike in antisemitic attacks around the world, including in the united states. the fbi recently warned anti-semitism is reaching historic levels. its data shows jewish americans make up 2.4 of the public, but they're the targets of more than 60% of religious hate crimes recorded in this country. since october, jewish day schools have closed or had to hire extra security, synagogues have gone into lockdown, and college campuses in particular have seen a surge in antisemitic incidents, including some assaults. over the next hour, cnn's dana bash explores the roots of anti-semitism in america and how they've spread. you'll also hear from some who have personally experienced threats and attatacks in the pa months and have started hiding their jewish identity in public out of fear for their safety. sunday, october 29th in southern russia. barely three weeks after the october 7th attack on israel by hamas, the deadliest day for jews since the holocaust, an angry mob stormed the tarmac and rushed the plane that had just arririved from t tel aviv. theyey were huntnting for jejew. > they wereren't sayingng gi the isisraelis, whwhich would d bebeen terriblble any way.y. they arere yelling w where are jewsws.. wherere are the e jews. that is plain old anti-semitism. >> reporter: ambassador debra lipstat is the spepecial envoy monitor and d combat ananti-semitisism. she wawas sworn inin in 2022, , alalready risising hate araroun world. since ththe attack o on israel, has s your role become more vit? >> w we began toto see, firsrst surge anand then a s spike, the explosion and now a tsunami of anti-semitism worldwide. in paris, in london, in germany. inin australiaia, it was g gas jews. get rid d of the jewews. let's have a jew-free zone.. it's's not aboutut being proro- or anti-i-israel. it's about anti-semitism. you know how when the yellow light is flashing, anti-semitism is like that amber light. and what i it's signalaling is anti-s-semitism isis coming anas a a threat to o democracy. >> repeporter: if f anti-semitis a telltatale sign ththat a demoy is threatetened, what t does it about ththe united s states rig now? >> it's disturbing. it's disturbing. >> reporter: this new wave of jewish hatred is causing historic levels of anti-semitic acts in america. >> we've just never seen a surge like this before. literally we've seen the highest numbers that adl has ever tracked in terms of acts of harassment, vandalism and violence. 202022 was thehe worst yeaear e. and ththe numbers s already sos have expxploded since october t 7th. >> reporter: but anti-semitic incidents up nearly 400%, according to adl data. >> while the jewish community is struggling to make sense of that madness that horror, it has been incredibly painful, compounding the grieief and the e sense of anxiety to see the world turn on the jewish community, to see protesters in places here in the united states attacking jewish peoplele in broad d daylight, , vavandalizing, quote, zizionist bubusinesses. i ththink if we e try to undnde why is thihis happenining in th momoment, i ththink we havave s anti-semitism normalized in recent years. as t that seeps s into the c cu and sort o of poisons s the bloodstream, it then allows people to think, oh, it is okay to make it open season on jews. >> this past month we had 770 incident repeports.. therere is no ququestion that t incidedents are gogoing up.. one e of the thihings we've e o- >> reporteter: mike mamasters ie ceo of the sececure commmmunity networork, a 24/7 command cecen where ananalysts mononitor all way dodown to the dadark webeb threreats againsnst jews. >> this s is our j jewish sesec opererations comommand centeter. this i is the natitional hub. >> i'm c curious to o see how much i it changed d since t last timime we were e here. i i first met him in 2 2022 alr reportrting on a d disturbing g inin anti-semimitism i in ameri. but t october 7th tookok scn's' toto another l level. >> says acactive now.. 31. what d does that m mean? >> t there are 3 31 risk eveven occucurring in p proximity t to jewiwish proximimity, right t n across the couountry. >> how mucuch more of f nonspec threats are you seeing n now versus octctober 7th? > 149 sincece october 7 7th. onon average a month before tha was clcloser to 5050. those are an individual that is threatening to kill jews. we've had multiple threats of jewish day schools around the country receiving phone calls of individuals saying we're going to come in and kill you and imitating the sounds of gunfire. indianana, virginia, washington d.d.c. and othther states.s. since ococtober 7th.h. >> reporter: it opened the flood gates? >> it opened thehe flood gates. >> reporter: and flood waters are breaching the walls of college campuses across the country. >> at harvard university in cambridge, massachusetts -- a pro palestinian rally clashed with supporters of israel. >> at george washington university, glory to our martyrs among the messages projected on a library wall. >> some of the worst the stanford professor who literally herded jewish students into a corner, humiliating them. the assault at uc davis of a jewish student putting up poststers of hosostages justst e sure thahat they arere not forgn and being physically assaulted in the process. a very similar instance at columbia. >> in many cities and many campuses, missing persons style posters being torn down. >> no, no, no. >> reporter: the posters of kidnapped israelis have become a flash point. with confrontations going viral on social media. >> he's bothering me. >> you're surprised? show your face. show your face. >> youou are not a allowed -- - >> they y tear them m down beca ththey don't see them as p peop. ththey see them as sometething inferioror. theyey see them m as somethihin subhbhuman. this is the destination where anti-semitism takes you. >> it's children. it's innocent people. >> w what about the children in palelestine? >> that isis one of ththe thing find m most distururbing. > reporter:r: why? > these areren't soldieiers were taken in battle. these were civilians who were taken away. these were women who were raped and then taken. these are babies. but to tear down the pictures and to do it with such an aggressive attitude. it's a a form of hate. it's a form of hate. it's a form of contempt for life. > reporter:r: anti-semimitis jewish hate has been part ofof e fabricic of societeties for millennia.a. the difference between that and what we see in modern times is what? >> the difference in terms of anti-semitism today y is that i blends a l lot of the e traditi notions of nefarious jewish popower being used to tatake advavantage of o other peoplple a veryry specific c anti-zionind anti-israel set of narratives. >> jew hatatred, anti-semitism dedeeply bakeded into not t jus weststern societety but muchch world. it's's very hardrd to eradicica. anti-semititism has bebeen call the longesest or the o oldest hd with g good reasonon. soso, this sorort of let t the f for r many anti-i-semites fofor a few decacades. it hasn't t been takenen seriou. people h have said, , well, it't as s serious as s racism. itit's not as s serious asas homophphobia. itit's not as s serious asas mi, misogyny, et cetera. or what you'll often find is amongst university admininistrators, , at least j kikids, they c come from w welld familieses. it's almosost falling g into th antisemititic trope. jews are p powerful, s so why a they comomplaining? jews are successful, why are they complaining? >> call it out for what it is. when george floyd was murdered, it would have beenen so inapappropriate e to say, wewe n the racismsm that was s behind and ththe homophobobia and theh anti-s-semitism, b but somehowo itit comes to o anti-semititism couldn't be called out on its s own. it couldn't stand on its own. >> what dodoes the whahat about do? >> it dilulutes anand d to a a degree rationalilizes and/oror justififies. i wantnt to be alslso exactly y, crcriticism ofof israeli policy not anti-semitism. but,t, when you u question t tht of a jews to a n national identityty, when youou question exisistence of a a jewish ststau move beyeyond the popolitical. >> reporter: anti-semitism in the u.s. is now exploding on both sides of the political spspectrum. in recent history, the anti-jewish hate that has s explodeded into viololence has fromom the right, from right wi extremiststs. what is happppening on c colleg campuses tends to comeme from t left. > yeah. i i mean, therere's no queuestit the cultlture on camampus, when comes to a anti-jewish sentimen is comoming from left wing g gr anand allianceces that arere alt around this demonization of israel. wherever j jewish stududents a just trying to go about living their lives on campus. >> repororter: so whwhen you ta about demonization of israel, a lot of prorogressives s would s yoyou can be a anti-israel and anti-s-semitic. that's notot true anymymore. >> we haveve seen the e line ben anti-i-israel sentntiment and d anti-semititism completely crumble. when students have been physically assaulted at university of georgia, at uc davis, at other campuses, no one is asking them about their views ofof the israeaeli/palestitinia coconflict. this line has completely broken down. >> reporter: as war rages on, there's little hope of domestic attacks letting up. >> the death of a jewish man at duelling protests in southern california is being investigated as a homicide. >> in the last week, we have seen a jewish man assaulted and killed in southern california. we saw a woman try to drive her car into what she thought was a synagogue outside ofof chicago. these look like outliers until you pull back and you realize, they're actually data points on a trend line of intensifying ananti-semitisism and incrcreas probability of violence. >> reporter: ahead -- >> it really went from 0 to 100. >> reporter: clashes escalate on american campuses. ♪ >> reporter: new orleans, louisiana. duelling pro-palestinian and pro-israeli rallies near tulane universisity turned viviolent. >> they were chanting "israel,l isisrael, you u can't hihide, w charge you with gegenocide fror the ririver to the sea." >> reporter: when you hear from the river to the sea, what does that mean to you? >> they want to wipe us out. they want us gone. they don't want a two-state solution. >> it is the c call for ththe annihihilation of f israel. and in a s sense the e exterminn of the jewish people. >> reporter: tulane students dylan mann and panin that sasasn saidid the prorotests onon oppo sides of the street began peacefully. >> we felt each other's presence. there wasn't really a sense that we were attacking each other. you knknow, idealologically ata popoint. >> reporteter: when didid it tu? >> they would call us genocide supporters. we would say you're supporting genocide and some ofof their support fofor hamas. you know, they call us colonizers. we call l them terrororist susupporters. >> yes, , there werere things w shououted back a at them butut really t took a turn the secono the boy y pulled outut that fla from the truck. and took out a lighter. >> reporter: violence erupted when a pro-palestinian demonstratoror in the back of a pickup truck started to light an israeli flag on fire. >> a student on the jewish side he ran andnd tried to o get bace flag t to save it t from beingn burneded. therere were twowo kids in t th of the truck. one was holding the israeli flag and one was holding the palestinian flag on a very large pole. once the jewish student was able to retrieve the flag back, he started getting bashed over the head repeaeatedly withth that p. and whwhen i saw t that, that'tn i i ran in. i was trying to just get him out of the situation. >> reporter: then dillen was beaten and attacked by two older men, he says were not college-aged. >> i was completely blind sided by a man with a megaphone who hit me very viciously over the nose, which broke my nose. i went into complete shock. i went deaf for a couple seconds.s. i went b blind. maybe for a second. >> reporter: you're draped in an israeli flag. you're holding a photo of a jew beining held hosostage in gagaz you'u're gettingng beaten upup. >> this wasn't a pro-hamasas rally.y. atat least not in name. this w was what wawas called a pro-paleststinian rally. and it was still violent. you know, assaulting a jewish person isn't going to free palestine. and i think almost every single jew would agree that it is an utter tragedy ththe amount o of civilians who have died in gaza. and d while we're thinking that we're thinking a lot of these people in this crowd who are saying these sensible things are also calling for the destruction of israel for referring to zionism as genocide. and so, whwhen you're e not abl separate t the radicalal ideas ththe sensiblele ones, youou kn that's when it gets dangerous. >> reporter: in a statement, tulane's president michael fitts said, we stand against all forms of violence and hate, including anti-semitism, islamophobia and racism. a line was crossed, and we will do everything in our power to ensure it is not crossed again. and we still have much work to do to heal and unite our community. >> free free palestine! >> from the river toto the sea. > from the e river to the se! >> sinince octoberer 7th we hah seenen so much c conflict bubbl up on collllege campususes acro the coununtry. for jejewish studedents in paparticular, , they are g goin trtrauma to trauma. and most o of them felelt incree trtrauma watchching so manany it israelelis slaughthtered on oco 7th. and while they were mourning that, while they were feeling the threat and fear of what happened, in many cases people they knew or felt connected to, there were mobilizations of anti-israel ststudent groups an other groups coming to campus to turn what had been a mass murder into an opportunity to further demonize israel. >> we've had 148 incidents reported to us on college campuses since october 7th. that is an increase of severala hundred pepercent fromom the mo prior.r. >> tensions on harvard's campus flared when a coalition of student groups signed a letter the very night israeli authorities said civilians were raped, beheaded and burned alive, stating israel was, quote, entirely responsible for the hamas terror attack. on october 31st, student at cornell university was arrested for allegedly posting online he would, quote, bring an assault rifle to campus and shoot all you pig jews. he also allegedly threatened to stab and slit the throat of any jewish males he sees on campus, to rape and throw off a cliff any jewish females, and to behead any jewish babies. the studenent's motherer releas statement saying he hahad menta health s struggles. > we get t risk e events frf around t the world.. >> the p posts were e caught fr scn's s command cecenter. >> we have team members that had been o on the cornell campus working with thehe administrtra and law enforcement. >> m members of f your organani are e on the groround at cororn teaching the students how to be more safe? >> yes. >> reporter: the dean of the university of california berkley school of law, who is jewish says he's never seen the level of anti-semitism at universities including among faculty as rampant as it is now. >> i was stunned and saddened to see statementsts online celebratating the hahamas terro attack. i could read you a few examples. for instance, students for justice in palestine called the terrorist attack, quote, historic win for, quote, the palestinian resistance. a columbia professor called the hamas massacre, quote, awesome. and quote, a stunning victory. chicago art professor posted a note that said, quote, israelis are pigs, savages, very, very bad team, irredeemable excrement. may they all rot in hell. if this is anything-on-jewish pepeople beingng killed wowoulde say thisis? if they did, wouldn't they be widely condemned. >> at george washington university the groups students for justice in palestine recently projected antisemitic tropics outside gellman library. quote, free palestine from the river to the sea.. and, quotete, glory toto our mamartyrs. >> imamagine a wororld in whici after r the murderer of georgegd sosomeone was s projectingng me likeke about prorotect the p po and georgege floyd wasas guilty. how offensive would that be? >> reporter: in this case, gw's president ellen granberg said, quote, these images included antisemitic phrases that have caused fear and anxiety for many members of our jewish and broader gw community, and we wholly denounce this type of conduct. >> i w went to gw. i'm a proud alum. i i studied in that librbrary f four yearsrs. i can't imimagine whatat it fee lilike to know that thesese hat imagages and phrhrases were e projecteted on the o outside oft buililding. >> to see e many peoplple sitti there e under thesese projectit was very uncncomfortablele and disheartenening to seeee. >> reporteter: galali isis a se out gw, aviv a f freshman. his grgrandmother r lives in i . >> reporter:r: did she c call y? >> y yeah. > reporter:r: what did she s? >> she asksked if evererything okay. what's goioing on herere. and just want memed to explalai heher what i'v've been seeing o campus. and if it's reallyly as bad asau see it is s online. >> r reporter: s so this is s y grandmother in ashkekelon, o on border with gaza, worrieied abo you on a colollege campus s in america?a? >> y yeah. >> your mom totold you to take your mezzazuzuzah thatat hangs outside e the dooror. yoyour mom tolold you u to put inside. >> yeah.h. >> did you?? >> yeah,h, i did. and ththen i also o she asked d chchange my naname on uberer anr apps thahat have my y name on i becaususe my name e is israelil byby reading i it you woululd km jewish.. she wantnted me to s switch tha wellll just to b be safe. >> i reaeally feel l like we coo collllege to leaearn and to o m people w who are so different fm us. and maybe e have different political ideas s or who havaven raraised in a a different t rel. and d right now w i feel likike can't hahave those c challengin conversatitions becaususe i fee ifif when i shshare my opipinio will be shut down. >> reporter: unchecked anti-semitism has led to high profile donor backlash at harvard, c columbia, t the university of pennsylvania and others. >> school for whatever reason can't feel like it can defend israel and attack evil and call out hamas for what it is, the things that they did were evil. and they weren't willing to say it. >> reporter:r: some of t the nation's's moist prominent law firms warned elite colleges to crack down on anti-semitism or face recruitment problems. >> the madness has to stop and candidly in the case of tulane and elsewhere, we need our university administrators to take control of the situation, to bring some order to this chaos in the way it's being directed against jewish students. >> reporter: we reached out to cornell, columbia, tulane, george washington and eight other universities who have experienced anti-semitism on campus for an interview with the school's president. they all declined. columbia did announce on friday they suspended two pro-palestinian student groups for repeated violation of university policies. >> it's very depressing. it's very depressing. have we failed? >> reporter: what's the answer? >> from what i've seen, we certainly haven't succeeded in critical analytical thinking. something has gone wrong worldwide in higher education. and it's got to be resolved. >> reporter: uc berkley's law school dean said his school has done a lot to address anti-semitism. >> we require all of our law students to go through bias traiaining that t includes anti-semititism as welell as ot forms of bigotry as well as i've certainly been willing to express mymyself in condemning anti-s-semitism whwhen i see i . and i thinink that's i importan a dea