Likely Republican nominee Pat Toomey trails both of the Democrats who are vying for their party’s nomination – Senator Arlen Specter and Rep. Joe Sestak – in potential match-ups for next year’s U.S. Senate race in Pennsylvania.

A new Rasmussen Reports telephone survey of Pennsylvania voters shows Specter leading Toomey by 11 points, 50% to 39%.

Sestak bests Toomey by a narrower 41% to 35%.

But incumbents who poll at 50% or less are generally viewed as vulnerable, and Specter, who recently switched parties to become a Democrat, may face a bruising Democratic primary. Also, Toomey could be helped or hurt by the state of the economy and the level of President Obama’s popularity 17 months from now.

A former congressman who unsuccessfully challenged Specter for the GOP nomination in 2004, Toomey fares much better in the favorability race.
Fifty percent (50%) of Pennsylvania voters have a favorable opinion of Toomey, including 15% whose view is very favorable. Thirty-five percent (35%) have a unfavorable view, with 16% very unfavorable. But 16% don’t know enough about Toomey to have an opinion of him.

Specter, who has represented the state in the Senate since 1981, is viewed favorably by 53%, with 24% very favorable. His unfavorables total 43%, with 26% very unfavorable. Just three percent (3%) are not sure what they think of Specter.

Forty-two percent (42%) have a favorable opinion of Sestak, a second-term congressman from the Philadelphia suburbs who is defying party leaders to challenge Specter. Of that group, 12% view him very favorably. Thirty-two percent (32%) regard Sestak unfavorably, including 11% very unfavorable.

But a large number of voters (26%) don’t know him well enough to have an opinion.

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Specter leads Sestak by 19 percentage points – 51% to 32% - in an early look at the 2010 Democratic Senatorial Primary in Pennsylvania.

Specter, a longtime GOP senator, switched parties and became a Democrat several weeks ago just after a Rasmussen Reports poll in the state showed him trailing Toomey by 21 points in a likely Republican Senate Primary match-up.

Specter acknowledged that one of the reasons he changed parties was a fear that he might lose his own party’s nomination even though he felt sure he had a better chance of winning the general election than Toomey.

Particularly damaging to Sepcter among Pennsylvania Republicans was his vote for President Obama’s economic stimulus plan, one of only three cast by Republicans for it.

Sixty-eight percent (68%) of Republican voters favor Toomey in a match-up with Specter, who draws 74% of the Democratic vote and 23% of Republicans.

Sixty-six percent (66%) of GOP voters support Toomey in a race against Sestak, who earns 64% of Democrats and just 13% of Republicans.

As part of the effort to coax Specter into switching parties to move Democrats closer to a filibuster-proof majority in the Senate, both the president and Pennsylvania’s Democratic governor, Edward Rendell, endorsed Specter as the party’s Senate nominee in 2010. They also promised to campaign for him. Sestak, angry like many Democrats in the state about a longtime Republican suddenly becoming the Democratic candidate for Senate, has vowed to challenge Specter for the nomination.

Fifty-three percent (53%) of Pennsylvania voters now approve of Rendell’s job performance, while 46% disapprove.

Sixty percent (60%) approve of Obama’s job performance, while 39% disapprove. This is slightly higher than the national findings in the Rasmussen Reports daily Presidential Tracking Poll.

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