WASHINGTON U.S. Sen. Arlen Specters decision to bolt the Republican party and become a Democrat -- has raised fears his move could bolster chances of the Senate passing the Employee Free Choice Act.

However, Specters support for the bill isnt seen as being automatic.

The oft-times independent-mind Specter said in a Senate speech in March he would vote against the bill that would make it easier for unions to organize workplaces. (See April 15 Bus & Motorcoach News.) Specter repeated his vow to vote against the proposed law after making his switch announcement.

However, some political observers think it will be harder for him to sustain his opposition to the bill as a Democrat.

Specter was one of three crucial GOP votes that helped pass President Barack Obama's $787 billion economic stimulus act. That vote outraged many Republicans in Specters home state of Pennsylvania.

Specter said he switched parties because the GOP had grown too conservative and because he stood little chance of winning the Republican primary for Senate because of his vote for the Obama stimulus bill.

Specter plans to run for re-election in 2010 as a Democrat.

With the expected seating in the Senate of Al Franken, whose election victory as a Democrat in Minnesota is being challenged in court by the incumbent Republican Norm Coleman, Specter's switch gives Democrats the 60 votes needed to automatically break a GOP filibuster and advance legislation.

However, Specter said he would not automatically side with the Democrats.

"My change in party affiliation does not mean I will be a party-line voter any more for the Democrats than I have been for the Republicans," he said. "I will not be an automatic 60th vote for cloture."