Larry Sabato at the University of Virginia has long since anointed former Florida Gov. Jeb Bush as the "nominal frontrunner" for the Republican presidential nomination in 2016. It's partly due to the lacklusterness of the opposition (third time's the charm, Mitt) and partly due to the fact that he's the only Republican so far to have officially announced an exploratory committee into a candidacy. But Jeb Bush has a fairly obvious advantage that comes into play not just in the general election but in the nomination fight, too: He's from Florida.
This may be less important for the general election than you think. While Mitt Romney's decisive loss in Massachusetts in 2012 and Al Gore's loss of Tennessee in 2000 probably burn sharply in the minds of the two men (probably more so Gore than Romney, since winning any other one state would have won Gore the presidency), those two are exceptions to the general historical trend: presidential candidates almost always win their home states. Before Gore, the last candidate to lose his home state at all (while winning at least one other state) was George McGovern, who lost his home state of South Dakota by over 8 points in 1972, and the last candidate to lose his home state while winning the presidency was Richard Nixon, who didn't need New York to win the presidency in 1968. (Nixon therefore belongs to an exclusive club along with Woodrow Wilson and James Polk, the other two presidents who were elected without the support of their home states.)
Even so, that may not be so much due to a "native son" effect as much as it's a result of the nomination process working. Democratic primary voters will probably nominate a moderate-to-liberal candidate; these candidates are easiest to find in places like New York, Massachusetts, Illinois, California, and so on. Those moderate-to-liberal candidates will likely win New York, Massachusetts, Illinois, and California not necessarily because they're from one of those states, but because those states tend to vote for moderate-to-liberal candidates anyway, especially when given the choice between that and a moderate-to-conservative candidate. Of course, in a state as close as Florida is at the national level, being from there might make a difference. But for someone like Hillary Clinton (New York) or Rick Perry (Texas), there is no real home state advantage to make use of.
Primaries, though, are different. In a primary, it's no longer a broad spectrum of voters comparing the moderate-liberal candidate to the moderate-conservative candidate; it's now the right side of the political spectrum trying to pick its favorite moderate-conservative candidate out of a bunch of conservative candidates (for the Republican primary, that is). This means distinguishing between candidates ideologically is much more difficult, and other factors may come into play. One might be electability--does even the most partisan of Republicans really believe that, barring a massive, 1929-sized economic implosion, that Ted Cruz can beat Hillary Clinton? But another easy factor could be home state. I, as a New Jerseyan, might vote for Chris Christie in the Republican primary since he's from the state, and I know I can trust a New Jerseyan to serve the functions of the office well.
