IMO (because I have nothing to back this up) the Republicans threw in the towel when they allowed McCain to even run.
He's not what they needed to win. They needed someone who was basically a knight in shining armor. The exact opposite of the last 8 years.
They presented McCain, who's presidency would simply be 4-8 more years of the exact same.
Pallin is simply their attempt to spit-polish the McCain team. If you look at her, or listen to her, she's an air-head soccer mom. They chose her because she looks good on camera as well as trying to counter-balance the "first black man in the white house" claim the democrats have with Obama with their own "first woman in the white house" claim (ignoring the simple fact that it's black president vs. woman vice president).
Basically, the whole thing is the Republicans trying to shore up their bet for the 2008 election with a pair that will allow the party to look good even as they lose.
Yes. I'm saying the previous 8 years guarantee the Republicans don't stand a chance because the White Knight they needed didn't exist in their party. They don't attract, and don't recruit, that kind of politician.
Now, if they had pushed Palin as their Presidential nominee with McCain as her Vice President...they might have done a bit better assuming they spun things harder and were able to pass Palin over as more of a go-getter and less an air-head soccer mom. Unfortunately, her record in Alaska dashed that hope.
Wait for the 2012 elections. You'll see the Republicans bring out their big guns again if Obama doesn't have a perfect presidency. Any mistakes and they'll put him in their crosshairs immediately. It will be Clinton all over again scandal-wise.
I personally expect something gang-related that's complete and utter crap yet manages to score a surprising amount of front-page media coverage for how bad it smells.