In one of the clearest signs so far the liberal activists will not give up on a primary challenge to Arlen Specter, has launched a new ad against the Pennsylvania Democrat.

The ad swipes at Specter for opposing mortgage reform, and reminds viewers the he has taken $6 million from the financial industry.

"What did he do?" the ad asks. "Exactly what the banks wanted. And now millions of people will lose their homes because of it."

Meanwhile, a coalition of liberal blogs and labor groups have launched an online straw poll asking activists to weigh in on whether Rep. Joe Sestak (D-Pa.) should challenge Specter. As of now, 88% favor a primary.