But Democrats can keep sending up the likes of Cynthia McKinney or Edwin Edwards and that's evidently OK.
Well, the Republicans have two things going against them:
1) The demographical move in this country is leaning for voters to become Democratic.
2) The media is clearly biased (as a whole) for Democrats.
As a voter used to vote more Republican and now more Democratic, I'll be the first to admit that, but the fact appears that the "image/perception" of the Republican Party is that it is stuck in the 80s as if nothing has changed since then. Catering to a dwindling base isn't going to cut it and now, gay marriage is legal federally. So, they've lost that battle socially that Karl Rove and George Bush used big-time as a fear point in the '04 cycle (it proved to be helpful in Bush's narrow re-election).
Add to it, that a lot of the "traditional", socially conservative base is now old and starting to die, literally. Things do change, and I believe a major economic event (i.e. another depression, which is coming) could turn the tables. Back in the 80s, the Democratic Party looked totally lost, as the party base shifted from the south to the northeast and industrial Midwest. They just kept losing, nominating one "liberal" after another with a dwindling party base. Things have changed though as the country has gotten less white and as younger voters, starting with the '00 election have become very strongly affiliated with the Democratic Party. Few if any of my generation cared about Bill Clinton's ethical dirt. What we saw was a booming economy (his doing or not) and Newt Gingrich essentially running himself into the ground growing up. It did big-time damage to the GOP image.
There was evidence, however that in '12, the "baby" voters (18-21), may not be as affiliated with the Democrats. I believe Romney broke even with Obama with them in '12 and may have even won their vote, but it was with minorities and voters 22-35 where Romney and McCain got crushed.
So, now what?