If Hillary Clinton runs, which Republican has the best chance of beating her?

[Mister Mets]

The strongest potential  Republican nominees against any candidate seem to be Chris Christie, Marco Rubio, Susanna Martinez, Brian Sandoval, Jon Huntsman and Kelly Ayotte.

I don't know how well Christie's brash demeanor would play when he's on a debate stage with a 68 year old woman.

There may be better optics with Marco Rubio, who would also allow voters to pick between two milestones, rather than the first female President and a white guy. Plus, he would be able to seize the "new" mantle.

Kelly Ayotte is pretty good at hiding her conservatism, someone who can appeal to primary and general election voters. And it means that a vote for the Republican would also be the vote for the first female President.

Jon Huntsman might be better at seizing the change mantle, appealing to dissatisfied Obama voters.

Susanna Martinez would be a bigger milestone than HRC, and has some interesting contrasts in her background. She can be a strong contender in the Western swing states. As a prosecutor turned small-state Governor, she hasn't really been involved in major controversies. She may not be ready to run as a presidential candidate, but the primary would likely stop her if that was the case.