Obama Campaign Advisor Derides Romney SuperPAC Heads as "Contract Killers"

On the same day the Obama campaign revealed the first in a series of political ads devoid of political attacks, Senior Campaign Advisor David Axelrod derided several Romney backers as "contract killers."

In a conference call with reporters Monday, Axelrod said the positive spin on the new ads, focusing on Obama's accomplishments rather than reverting to political attacks, doesn't preclude the campaign from reacting when it sees fit.

"We're also going to be prepared, and I want to be clear, to respond to the attacks that we expect to continue from-- not just from the Romney campaign but from the Karl and Koch brothers contract killers over there in SuperPAC land, who are going to continue to pound away on behalf of Governor Romney," Axelrod said.

"We will respond vigorously," he added.

Charles and David Koch are billionaire oil industry brothers who fund "Americans for Prosperity."

Bush alumni Karl Rove founded "American Crossroads."

The administration originally fought against the political advocacy groups known as SuperPACs, which have limited reporting and funding restrictions. The president his since made a turn-about, not only embracing the idea, but backing a SuperPAC working on behalf of his re-election.

"Priorities USA Action" was co-founded by two former Obama staffers.

The Obama camp has at times distanced itself from the group's actions, but in the case of Mitt Romney's SuperPACs, Axelrod said Monday, "We will treat every ad that comes from those entities as an ad from Governor Romney. We will compare our record and our vision with his and we'll let the American people decide."

The $25 million dollar ad buy for the month of May began Monday with an ad entitled, "Go," which laid out the president's record, from the auto bailout to killing Osama bin Laden. The ads are running in Virginia, Pennsylvania, Ohio, Nevada, New Hampshire, Iowa, North Carolina, Florida and Colorado.