HARRISBURG — A pair of polls released Wednesday painted conflicting pictures of how U.S. Sen. Arlen Specter, R-Pa., might fare in next year's Republican primary.

A statewide survey by Connecticut-based Quinnipiac University showed conservative Pat Toomey leading the fifth-term incumbent 41 percent to 27 percent among Pennsylvania Republicans in a one-on-one match against Specter, with 28 percent undecided.

Toomey nearly defeated Specter in the 2004 primary, losing by barely 17,000 votes out of 1 million cast. The former congressman from Lehigh County, who now heads the Club for Growth in Washington, is considered likely to demand a rematch in 2010.

Yet the Quinnipiac poll also showed that three out of four GOP voters said they don't know enough about Toomey to form an opinion about him.

It showed that 45 percent of all Pennsylvania voters hold a favorable opinion of Specter — down from 56 percent in November — but nearly half of Republicans view him unfavorably.

A poll by Franklin & Marshall College in Lancaster asked Republican voters to consider a primary with multiple candidates. Forty-two percent said they were undecided, 33 percent favored Specter, 18 percent supported Toomey and 2 percent were for conservative Peg Luksik.

Specter angered many of the state's Republicans last month by casting one of three GOP votes for the federal economic stimulus package. Toomey has seized on that anger in courting speculation he will run.

The poll results were released one day after Specter announced that he would oppose a bill to make it easier for workers to unionize — dashing the hopes of union leaders who hoped he would provide the crucial 60th vote needed to overcome an expected GOP filibuster later this year.

His decision to oppose it "was huge for him with the business community," said Terry Madonna, a professor and pollster who directed the Franklin & Marshall survey commissioned by several newspapers and TV stations.