The Massachusetts Senate race has gotten quite heated, with Republican Gabriel Gomez calling Democratic Rep. Ed Markey "pond scum" for a web video that invokes Osama bin Laden.

"You know I've got four young kids, and they've got to sit there and they've got to see an ad with their dad, who's a SEAL, who served honorably," he told a reporter after speaking at the Newton-Needham Chamber of Commerce. "And for him to be as dirty and low, pond scum, to put me up there next to bin Laden, he's just got to be called what he is."

He added, "Congressman Markey's been around for 40 years, he knows exactly what he's doing."

Markey's web video highlighted the fact that Gomez was a spokesman for a conservative super PAC that criticized Obama's handling of information about the death of Osama bin Laden. Now Gomez is out with his own television ad saying "dirty Ed Markey" ran ads "smearing Gabriel Gomez, comparing him to bin Laden" and "blames Gomez for the Newtown shooting." Markey's campaign has pushed back, saying the ad makes false accusations. Spokesman Andrew Zucker called it "desperate."

The two candidates are vying for the seat vacated by Secretary of State John Kerry in a special election that will be held June 25.