Over at the Red State blog, a series of diary entries from Myra Adams has been raising the questions that Republicans interested in winning back the White House really need to be asking. Adams writes about the several (16 that she finds) institutional advantages a Hillary Clinton run for the White House over any other candidate, as well as the steep electoral college challenge any Republican candidate will face against any Democratic candidate.
I think the one aspect Adams didn't hit on is the concept of the "Obama coalition". President Obama's electoral success isn't something unique in what types of voters voted for him (the only notable demographic that voted for him that traditionally went Republican are Asian Americans), but the real success of the Obama coalition was driving the turnout as much as possible. So the question isn't so much if these voters are Obama voters, but if these Obama voters can be relied on to vote for other Democratic candidates for President.
During the 2012 election, Karl Rove summarized what the Romney campaign needed to do to win the election: He needed to win all three major swing states (Ohio, Virginia, Florida), win back the two red states that Obama won in 2008 (Indiana, North Carolina), and pick up one of about a dozen smaller swing states. If any of the first two didn't happen, the Romney campaign would have to pick up several of the smaller swing states to catch up on the electoral map.
As we know, that didn't work out. Not only did the Romney campaign not win, but they didn't win a single one of the big three swing states. And even if they swept all three swing states, they still would've been four electoral votes short.
And while some may be quick to point out that many blue states have Republicans in elected offices from a state wide election, many of those were won in midterm 2010 elections, which not only had a different voting electorate but was very much a GOP wave election. The GOP can't rely on that happening during a Presidential campaign.
A lot can happen between now and November, 2016. But if I was at the RNC right now, I'd be hoping that the Obama coalition leaves with Obama, and crossing my fingers that Generic Boring White Guy gets the Democratic nod rather than Hillary Clinton or Vice President Joe Biden.