If you see an ad on my blog that says anything against Barack Obama, disregard it.
That's right, ignore it all. Of course I can't compel you to do anything whatsoever, so you're going to do whatever you want and more power to you. However I can say this: don't believe any ad you see on my site must necessarily reflect my own beliefs.
There's an ad on here right now that says "Barack Obama wants to BAN GUNS! Don't let him do it!"
I say, do let him do it. There are a boatload of guns out there getting bought up that shouldn't be legal to sell. Obama doesn't want to ban all guns and only a simpleton would believe that he does. Ads like this are just more right-wing, ultra-conservative rabble rousing.
Don't let yourself be roused. That's how you separate yourself from the rabble.