Which Republican candidate has the best chance against Clinton and why?

[Mr. Smith]

Paul, Rubio, and Walker.

[Publius]

Christie, like all big people, should be getting more love.  Governor of a blue state who could excite conservatives and attract moderates.  The center is begging for a guy who ostensibly rises above partisan politics (emphasis on ostensibly).  Christie could lock down the right, win the center, and even pull from the blues.  The question is--are Republicans ready to forgive?  Once he starts campaigning and we see his head to head with Hillary polls reflect the bump, the answer is yes.

Next I'd go Walker, if for no other reason than it seems like he already won a national election against a united left.

I think those going Paul are letting their bias cloud their judgement.  The hawks would stay home on him, and some might even secretly root for Hillary from the basement of their war rooms.

The Kasich poll numbers here remind us of the problem with online polls.

[Absentee Voting Ghost of Ruin]

Rubio. He can make a strong and positive contrast compared to Clinton, while still potentially appealing to moderate voters.

[dudeabides]

Governor Bush - he's got the right message, the right ideas, and the experience of both winning and governing.

[Publius]

And you trust the electorate to recognize its mistakes by 2016?

[Leinad]

John Kasich, Jeb Bush, and Marco Rubio, in that order.

Rand Paul has a history of really bizarre statements and generally out-of-mainstream views that forces him to clarify his positions and play damage control a lot. For example, when he questioned the constitutionality of Title II of the Civil Rights Act during his Senate campaign, or more recently when he made some wacky comments about vaccination.

He has has the potential to play well against Hillary, but he also has the potential to be the next Barry Goldwater, by saying something wacky at the wrong time and allowing Hillary define him as a loon.

I'd put Rubio ahead of Bush and maybe Kasich, and maybe Rand ahead of Jeb (I'm telling you, a Bush won't win), but I agree 100% with your second and third paragraphs.

Senator Rand Paul is awesome. My favorite senator, I'd say. But Candidate Rand Paul is shaky. He's trying to cover the libertarians, conservatives, and moderates at the same time, which is nearly impossible.

Rand Paul.

Why? Because he wants to audit the fed, curb the surveillance state, avoid war, and reform the criminal justice system.

I don't know why everyone thinks Rubio. Rubio won't attract enough support from minorities or independents.

Rand is by far my personal favorite in the field. He's the only candidate that seems likely to give me what I'm wanting: lower the influence of government both at home and abroad. I seriously doubt I'd vote for a major party if it's not him. But I try to keep my analysis separate from my ideology.

Rubio's likability helps him with the casual moderates. He's conservative enough to ignite the base, but I think the moderate swing voters and establishment can get behind him, too. He'll also have a better chance at Florida than possibly anyone else at all, and Florida is a must-win for the Republicans to take the White House.

Kentucky's a slam-dunk for the Republicans, Rand will struggle to get either the establishment or the conservatives without some great campaigning. Right now he's trying to sell himself to the entire big tent of the party--libertarians, establishment, conservatives, independents--and obviously that's a hard task.