>> it's something we did together, the last thing we did together. >> o'donnell: and it's election night across the country. we'll run down the key races that may foreshadow what could happen in 2020. >> this is the "cbs evening news" with norah o'donnell. >> o'donnell: good evening and thank you so much for joining us. we begin with a brazen attack on an american family leaving three women and six children dead. they were shot and their car burned. tonight a u.s. official tells cbs news one theory is the group was intentionally targeted by a drug cartel. the youngest killed were twins, just eight months old. eight other children survived, five with bullet wounds. they were part of an extended family, a religious community that long ago broke away from the mormon church. they have had run-ins with the local drug cartels before, but nothing like the vicious ambush that went down yesterday