The last time i checked the primaries (which admittedly wasn't all that recently) Romney and Santorum were neck and neck, with Ron Paul in a somewhat distant third. (I think Gingrinch was doing well for a bit, but then fell off again?)
So at this point it's still plausible that any of them could pick up the nomination. So in the worst case scenario of a Republican becoming president, if they caught Obama kicking a dog on live TV or something, who would you prefer? Romeny, Paul, or ...okay, who am i kidding? Romney or Paul?
On the face of it, i think i would prefer Romney. If he was elected and got everything he wanted he'd definitely set the country back a bit, but in another four or eight years we'd get someone else and hopefully we'd recover. On the other hand if Paul was elected and got everything he wanted... i'm really not sure where the country would be four years later, but i think it would take a looooong time to recover from it.
However presidents almost never get everything they want. In fact they rarely get most of what they want. They have to negotiate with congress to come up with deals that are at least somewhat acceptable to everyone. I don't think Paul could manage to convince congress to completely eliminate taxes, or switch us to a gold standard, or any of his other crazier notions. However there is a _small_ chance he could actually make some progress (or at least halt the decay) on getting us some freedoms back. Romney on the other hand would ask for much more mundane set of bad things, and thus would be much more likely to get a significant amount of what he wanted.
Of course i'd take Obama over either one of them (despite the number of things Obama has disappointed me on) but it might be interesting to see what happened to the debate if Paul was running against Obama. Would Obama try to distinguish himself from Paul by going more liberal on economic issues or more conservative on social issues? (It might be interesting to watch heads asplode as Obama promises to crack down even more on marijuana just to counter Paul.) Or would he try to co-opt some of Paul's more sane ideas so that the remaining distinguishing features would be his loony ideas?
In any case though i know a Ron Paul victory in the primaries is pretty unlikely. And Santorum would _probably_ be even less likely to win against Obama than Romney, but the idea of him getting even just the nomination is kind of abhorrent. So i guess i hope Romney wins? Yay? =P
(And yes, i know that Ron Paul is a racist dick, but really i have trouble believing that there are any white middle class religious conservative Republican who _aren't_ racists dicks. Maybe that's just my own stereotyping problem though.)