Republicans, breathe a sigh of relief. Forecasters are pretty confident that tropical storm Isaac won't hit the convention at which Mitt Romney will be nominated as the Republican presidential candidate. The storm is now expected to swing west of Tampa, sparing the grand event. But meteorologists say the area isn't entirely in the clear: the storm's course could still shift significantly once it hits the Gulf of Mexico. But for now, Republican officials can turn their energies to other worries—like keeping New Jersey Gov. Chris Christie in check.