Personally, I think the 'Pubs would do alright nominating Rubio with a nod towards the libertarians and/or Tea Party in VP'ing Rand Paul or Ted Cruz.
After this country's experience with the Dear Leader the chances of electing another first term Senator with no executive experience this election cycle is exactly nil.
For as deep as the Republican bench is purported to be I see alot of guys that will be ready next cycle or 2, but not right now.
The Democratic bench is non=existent (Liz Warren has zero experience and is already 65) outside of Hillary. She has frozen the field, and no one can raise a dime until she decides what to do.
What will make her run different this time around is that her polling numbers are actually much better than they were in 2008, and Clinton nostalgia is far more prominent now than it was then. Slick Willy might be the most popular politician in America, as his presidency looks the glory days to most people the further we get from it.
Couple that with the fact that feminists will finally get a chance to triumph putting their woman in the White House and I don't see how Hillary doesn't win the Presidency. If anything, I could see her winning in a major route. She will make some southern states competitive that loath Obama, as the working class whites have always gravitated towards the Clintons.
There are enough stupid people in this country that think voting for Hillary will really be a 3rd term for Slick Willy. Obama was able to rally a war angry base on the left last time to take the nomination away from Hillary (who voted for Iraq). This time around all factions are all in for her as there is no real mobilizing issue that could put her nomination in jeopardy.
I just don't see anyone on the right that would be able to be Conservative enough to win the primary and yet moderate enough to win the general. Willard ran into that problem in that he had to run so far to the right to win the nomination when it came time for the general comments like the "self-deportation" and the 47% just buried him.
Republicans need to run someone like Huckabee who is likable and an excellent communicator. He is not conservative enough to appeal to the base, but he would do great with independents and such as he is quick witted and easy to like. That combination did wonders for Reagan. Likeability is majorly important in an electorate that is as diverse as this one is and plays largely to Democrat party strengths as it gets less white by the cycle.