Jeb Bush can't win, as opposed to Ted Cruz - far too conservative for a general election, same applies to Rick Santorum - time to give up the ghost Ricky boy! Rick Perry! not going to happen! Rand Paul doesn't have the gravitas to make a credible run; Marco Rubio, nice and to much of a light weight; Chris Christie, bully and is no more likely to make it passed the true blue tea party conservatives than Mitt Romney; Paul Ryan, not presidential enough and is to much identified with congressional Republicans; Scott Walker has to win re-election first and being durable enough is iffy at the least, besides he has a brittle quality that will be likely his undoing. All the possible contenders are all as flawed in one way or another as Jeb Bush appears to be and I use appears advisably, yes the family name might condemn him, but he's not his brother and he seems to represent the happy face of Republicanism like Ronald Reagan and doesn't come across as angry as the likes of Cruz, Santorum, Walker do or identified with tea party extremism as Paul or Rubio are or a light weight like Ryan is. Bush can without doubt appeal to hispanics and independents alike and represents more of the open tent Republicanism as embraced by Reagan, it's a no-brainer. So yeah let the GOP nominate Santorum, Cruz, Paul, Perry, Ryan and the outcome is a dead cert, to lose big time; Rubio or Christie just to many imponderables so again we are back with Jeb again. Besides his presence on ticket, makes Arizona, Colorado, Nevada and New Mexico more competitive for Republicans, puts Florida out of reach for Democrats. I expect a good many Democrats will disagree with my "flawed" analysis as it takes them out of there comfort zone and Tea Party and hardline Republicans don't want to consider the idea that one of there "guys" might not have the electability to win; but that's where I believe we are.
I still kind of doubt Bush runs. If he does, I think Perry is his biggest challenger. If Perry could tone it down and be better prepared, he could possibly win.
Even if Bush wins the primary, he may too dull for the general election. He's not an exciting of a politican. Maybe if the democratic nominee is bad or more boring than him.
Who knows how 2016 is going to be, though. It could look awful for the democrats, it could look decent.