Actually, I would have for 2008, but I probably won't in 2012. I doubt that there's anything worse for our country than four years of Obama, which I expect to be more damaging than a thermonuclear war with Russia. We could and would rebuild after a war; I doubt that we'll have what it takes to repair Obama's mess when that neosocialist has finished trashing the Constitution and our economy.
Would I let Obama stay for four more years rather than vote for Mitt? Probably. It's like the local teens used your home for an overnight party, and it's trashed, with the walls, floor, appliances, and furniture destroyed. There'll be a little more damage if they stay for a second night, maybe a couple more walls taken down, but they've already done most of the damage that can be done. If your choice is to throw them out and not repair the damage or wait another night and then fix everything they destroyed, you might be better off waiting. Similarly, I'm not willing to put a RINO in after Obama. I want someone who will dismantle as much as possible of the socialist programs and restore the Constitution. Mitt Romney is not the man for that job - he's the one to hold the line at 90% socialism and valiantly protect the last 10% of what we have.