Pennsylvania Republican Pat Toomey — a conservative activist, former House member and political nemesis of longtime Sen. Arlen Specter — has been showing some serious political muscle since he launched a 2010 Senate bid less than three weeks ago. His campaign said Tuesday that he has raised more than half a million dollars over the 20 days since he announced his candidacy.

The money news came exactly a week after five-term Republican moderate Specter made his bombshell announcement that he was switching to the Democratic Party. Specter made the move to avoid a rematch of the 2004 Senate primary in which the Specter barely staved off an upset by Toomey, and was prompted by polls showing Toomey holding a big lead over the incumbent among the strongly conservative-leaning GOP primary voting base.

But the tout about the surge of early campaign funds also came amid simmering speculation that Toomey might soon draw yet another big-name primary opponent from the state Republican establishment: Tom Ridge, a former two-term governor.