I am not a socialist, the democrats want to take over 50% of my income
To me, this is what lost the election for Kerry. He said he was going to "rollback" the tax cut for "rich Americans". Anytime a candidate comes out and says "tax increase" they are asking for trouble.

On the flip side, Bush's unrealistic plan of letting some individuals divert a portion of their Social Security proceeds to a private investment probably cost him quite a few votes as well. A smart poitician doesn't even talk about messing with Granny's social security check. The blue hairs will show up to vote.

These were both major errors, but threatening a tax increase is the worse of the two evils.