this morning on "world news ta this morning on "world news now," taking aim, isaac is on the move in the gulf of mexico. and growing stronger. >> the monster storm is posing a major threat to new orleans on the eve of the anniversary of katrina. it's tuesday, august 28th. >> announcer: from abc news, this is "world news now." good morning, i'm john muller in for rob nelson. >> welcome back to the show. great to have you. i'm paula faris. the coming hours are crucial. and we'll get the latest on isaac's track live from accu-weather. also this half-hour, republicans are riding out the storm in tampa. we learn the star of the show, mitt romney, heading to the convention a little earlier than planned. they're condensing four days into three. speaker of the house john boehner telling diane sawyer last night, maybe we should just condense it from three from here