Sen. Arlen Specter (R-Pa.) likened his probable Republican primary opponent Pat ToomeyPatrick (Pat) Joseph ToomeyWH backpedals on Trump's 'due process' remark on guns Top GOP candidate drops out of Ohio Senate race Newly declassified memos detail extent of improper Obama-era NSA spying MORE to AIG executives who took bonuses while their company was receiving government support.

Echoing the more aggressive tack taken by his campaign, Specter said Toomey, chairman of the conservative Club for Growth, could not win statewide in Pennsylvania.

"When you take a look at his record, he's been contributed to the problem," Specter said Tuesday of Toomey's record supporting deregulation for corporations. "And now he wants a promotion -- he's like an AIG executive."

Specter said that this cycle's primary challenge would be a "different year" for Toomey, due to his background as an investor before entering the public sector.

"He's to the right of Rick Santorum -- Santorum lost by 18 points," Specter said of his former Senate colleague in Pennsylvania, who was ousten in 2006.

"I've survived because I've been willing to part from the party line when I think it's wrong," Specter said on MSNBC. "We just had this stimulus package. I was convinced we here on the brink of an economic meltdown."