Sen. Arlen Specter has lost some ground, but would win re-election comfortably if the 2010 Pennsylvania U.S. Senate race was held today, according to the latest Quinnipiac University poll released this morning.

Mr. Specter, who recently switched to become a Democrat, now holds a 46 to 37 percent lead over Republican rival Pat Toomey, the poll shows.

In the last poll May 4, Mr. Specter held a 20-point lead.

"While only 42 percent say Specter deserves re-election and 43 percent say he does not, more than the majority, 51 percent, like the job he is doing as senator," said Clay F. Richards, assistant director of the Quinnipiac University Polling Institute.

The poll also showed neither candidate faces any challenge in the primary and that voters believe that Specter, 79, is not too old to be reelected.

Republicans back Mr. Toomey, 73 to 16 percent. Mr. Specter leads 73 to 10 percent among Democrats and 43 to 33 percent among independent voters. He also leads 47 to 39 percent among men and 45 to 35 percent among women.

In a Democratic primary, Specter tops U.S. Rep. Joe Sestak 50 to 21 percent.

"[Specter is] still better off than he would have been if he stayed a Republican and faced a tough primary challenge from former Rep. Pat Toomey," Mr. Richards said. "But now that he's got President Barack Obama and Gov. Ed Rendell on his side, Specter should be able to hold the edge over the conservative Republican."

The poll was conducted from May 20 through Tuesday with 1,191 Pennsylvania voters surveyed.