Sarah Palin is earning her salary as John McCain’s attack dog (I’m not calling Palin a dog; just using a rather standard political phrase). The Alaskan governor took the gloves off this week-end and went after Barack Obama for his ties with Bill Ayers.

Ayers, the founder of the Weatherman and a guy who  thought bombing was a good political tactic,  is now a college professor. He and the junior Illinois senator have worked together on a number of education projects. Palin hit Obama hard for being connected to a 1960’s radical who seems to show no shame about his past.

“Our opponent though, is someone who sees America, it seems, as being so imperfect that he’s palling around with terrorists who would target their own country,” Palin said at a Colorado rally.

This strategy should come as no surprise. Ayers and Rev. Jeremiah Wright are weak points in the Obama armor. Obama’s narrative is a politician who is a firm believer in the country’s promise. Knowing these two gentleman throws that arc off the tracks and voters have every right to ask Obama about his ties to men most Americans would disagree with.

But let’s not delude ourselves. Palin understands numbers and from all the polls, she and McCain are chasing the Obama/Biden train. One way to catch up is to go negative.

When Obama gets the Wright/Ayers question tomorrow in the debate, he shouldn’t sigh or accuse McCain of dirty politics. He should just look in the camera and explain why he isn’t either man.