DENVER - Mark Halperin of The Page has the script of an Obama ad set to air in Ohio (and possibly other states) trying to defend and defuse the issue of Bill Ayers:

ANNCR: With all our problems, why is John McCain talking about the sixties, trying to link Barack Obama to radical Bill Ayers?

McCain knows Obama denounced Ayers' crimes, committed when Obama was just eight years old.

Let's talk about standing up for America today.

John McCain wants to spend $10 Billion a month in Iraq, tax breaks for corporations that ship jobs overseas, selling out American workers.

John McCain, just more of the same.

The fact the Obama campaign felt the need to cut an ad on Ayers suggests one of two possibilities: 1) the Obama campaign is demonstrating a lesson learned from Kerry and the Swift Boat Veterans for Truth in 2004, deciding to aggressively respond to the ad that popped us last week by the conservative 501C4 American Issues Project linking Obama to Ayers or 2) the American Issues Project ad is hurting Obama in Michigan and Ohio and they responded to it out of necessity rather than strategy. Hard to say which at this point.

Regardless, the McCain camp is more than happy to have a discussion about Obama's relationship with William Ayers, especially during the DNC. The McCain campaign fired right back with this statement from Brian Rogers:

"The fact that Barack Obama chose to launch his political career at the home of an unrepentant terrorist raises more questions about Senator Obama's judgment than any TV ad ever could. And the fact that he's launching his own Convention by defending his long association with a man who says he didn't bomb enough U.S. targets tells us more about Barack Obama than any of tonight's speeches will."

Obama's decision to respond was the flip side of the Catch 22 Kerry faced: if you take the issue on directly, you elevate it and allow your opponent an opportunity to bring it into the discussion and potentially make it part of the narrative. On the other hand, we know what happens if you take the approach of trying to ignore something like this.