MIAMI -- Will Jeb Bush run for president?

The former Florida governor is likely to be asked that question many times in the coming weeks as he makes appearances in Tennessee, New Mexico and Nevada. He'll probably be asked the same thing in Texas, where he'll bump into another possible 2016 presidential candidate, Hillary Rodham Clinton.

So far, Bush says he's undecided. But his answer is one of the most significant unknowns looming over the 2016 Republican presidential contest.

Bush is seen by many Republicans as an alternative to embattled New Jersey Gov. Chris Christie. A White House bid by Bush could be affected by his older brother's controversial presidency and potential Bush fatigue among the American public.