As an Obama supporter I find them entirely offensive - not just because they are trying to catch attention but because of the way they try to distort Obama's position.
Now, here's the solution - Click, Close window, repeat.
Why? Every time you click, you cost the advertiser money. I should know because I advertise my own business using click-ads.
So, the more offensive content of the ad, the more I click. If we all do the same we can run them out of business.
Obama/Biden '08