I can imagine there's a route for Bush to take the Florida/GOP Establishment slot over Rubio.
if Jeb Bush is running then Rubio isn't. I say Rand vs. Bush is more favorable than Rand vs Rubio.
I see these two candidates as the biggest threat to Rand.
Christie is damaged goods. Huckabee is dangerous because he could swoop in and steal Iowa. Rand has a better chance to win Iowa than NH.
Rubio may not be ready for prime time, and if that is true, then Jeb Bush becomes a more likely candidate. If Rand were running against Bush, even the lew rockwell blog might support Rand.
The keys for Rand to win:
1) keep doing what he is doing, which is basically imitating Ron Paul except for Iran and the Romney endorsement.
2) get Sarah Palin's endorsement.
3) get backing from the Koch brothers.
4) win CPAC at some point without looking like you are trying too hard.
5) win Iowa straw poll the same way, and be ready to win Iowa and get at least 2nd in NH.
6) win NV and SC, or at least 2nd in SC.
7) 2nd in FL