I'm going to actually push back on this. Yes, the 2004 election was depressing. But if you take a quick look at George W. Bush's approval rating, you'll see it was extremely low even before the financial crisis in late 2007 [1]. The war in Iraq was really unpopular during his second term. If you look at the electoral map in 2008, you'll also see Obama winning states that we can't even imagine a Democrat winning, because people used to be more open to voting for the other side. Politics in America has changed in a big way, and GOP politics has changed wildly.

[1] https://news.gallup.com/poll/116500/presidential-approval-ra... [2] https://en.wikipedia.org/wiki/2008_United_States_presidentia...