Dems... They have no really viable candidate other than Ms. Clinton. Even in local and state elections, the Dems have struggled to find candidates that can generate the dollars needed to win against the huge pocketbooks of the right. Personally, I believe Jim Webb would be a more electable candidate than Ms. Clinton. There's still time for someone to step up.
Pubs... The Pubs have a long list of hopefuls. That list will be whittled down as soon as the Kochs and Addelson decide who they want to elect. In the past two elections, a moderate has come out as the candidate... McCain and Romney. Immediately upon being nominated, the talking heads... Limbaugh, Hannity, and Beck have proclaimed the moderate as a mistake and sermonized to their cult followers to not vote rather than vote for the candidate. The Dem candidate has won more because of the split in the Pub party than a coming together of the Dems. Hence, I predict the money men will put their dollars behind a hard right candidate and he will be the candidate. I belive the Bush, Paul, etc.... common sense candidates... will be left behind. Walker might be it. But, I would think we'll see a Cruz or Rubio type succeed.
If we see and anti-immigration, war hawk, religious zealot, anti-same sex marriage, anti-social services, anti-regulation candidate from the right we will see dollars against a "get out the vote". It will all depend who gets off their couch and casts votes. If either Party leaves people unmotivated, under-excited... they lose.