Final debate over, Coakley unveils first negative ad

Democrat Martha Coakley, who leads Republican rival Scott Brown by 15 points among likely voters, according to a Globe poll, just put out an attack ad called "Lockstep Republican," seeking to link Brown with former president George W. Bush and the GOP leadership in Washington.

"Who is Scott Brown really? A Republican in lockstep with Washington Republicans," the narrator says, going on to attack Brown for resisting tougher Wall Street oversight, favoring Bush-era tax cuts that tilted toward the wealthy, and supporting a measure in the state Legislature to allow hospital personnel to deny emergency contraception to rape victims.

"In times like these, we can't afford a Republican like Scott Brown," the narrator concludes.

The decision to air such an ad suggests that Coakley and her fellow Democrats are nervous enough about Brown creeping closer that they felt the need to try to damage him in the eyes of voters.

Brown's campaign tonight put out a statement blasting the new ad.

"Instead of discussing issues like health care and jobs, Martha Coakley decided the best way to stop me is to tear me down," he said. "But the old way of doing things won't work anymore. Her attack ads are wrong and go too far. Massachusetts voters are paying attention to this election and they deserve better than tired, old gutter politics."