At some point in the 21st century, we will have an extremely unpopular Democratic president who will put all of safe/solid D states in play. Polarization isn’t going to last forever, and I assume we will revert to the mean and get back to having alternating landslides in presidential elections.
Bush's 25% approval rating, extremely unpopular Middle East quagmires, botched Katrina response, and even topping it off with an economic collapse less than 2 months (!) before the election didn't put safe R states into play unless you count Indiana. I don't see it happening.
Um...in addition to IN, Obama also won VA and NC, which had been ruby red states up until 2008. He also nearly flipped MT, which Bush won by 20+ points in the two elections previous. Also, a fact that is lost in the ash heap of history is that McCain actually ran a pretty stellar campaign. It is not remembered as such because of his eventual loss, but he actually did pretty well electorally given the conditions you mentioned. I think a generic candidate would’ve suffered a 1932-1980 style electoral bloodbath, and would have indeed put most Safe R states in play.
