Sen. Arlen Specter's 20-point lead over former Rep. Pat Toomey has evaporated in the last two months, leaving him in a dead heat with his potential Republican challenger in the 2010 Senate race, according to a poll released yesterday.

In the Quinnipiac University poll, Specter, seeking his sixth Senate term and first as a Democrat, was supported by 45 percent of the respondents and Toomey by 44 percent.

And voters, by a margin of 49 percent to 40 percent, say Specter does not deserve reelection, a near reversal from a May poll in which 49 percent voters said Specter deserved re-election, compared with 41 percent who did not.

"This poll was all about Specter, not Toomey," said Peter Brown, assistant director of the Connecticut-based polling institute. "For whatever reason, voters are less enamored with Arlen Specter than we have seen."

In a May 4 Quinnipiac poll, Specter led Toomey by 53 percent to 33 percent.

Brown said the poll numbers could reflect a broader "crankiness" by the electorate about the nation's economic climate.

"Pennsylvania is not an island," he said. "A lot of officeholders are seeing their numbers down. Voters are beginning to blame not George Bush, but those in power now."

Toomey, who nearly upset Specter in the 2004 Republican primary, does not "put a lot of stock in polls because they jump around a lot," his spokeswoman Nachama Soloveichik said.

But "it's clear that Pat Toomey's message of fiscal responsibility and bringing much-needed balance to Washington is catching on with folks all across Pennsylvania," she said.

The poll showed both Specter and Toomey leading party rivals by healthy margins heading into primaries next year.

In the GOP race, Toomey led Johnstown-based activist Peg Luksik by 47 percent to 6 percent, with 45 percent undecided.

Specter is ahead of U.S. Rep. Joe Sestak by 55 to 23 percent, with 19 percent of Democrats undecided. Sestak told reporters yesterday that his formal announcement would come within weeks, but he also said that he had visited all 67 Pennsylvania counties and was running for the Senate.

Sestak said the poll tells him that he needs to make himself more visible, he said in a statement yesterday.

"Few knew me before, but invariably they responded favorably both to me and what I represent," Sestak wrote in an e-mail. "The polls reflect that fact: 70 percent of voters don't know me well enough to make a decision. I have a lot of work to do, but the message of trustworthy leadership resonated."

The telephone poll of 1,173 voters was conducted over six days ending Sunday. The margin of error was plus or minus 2.9 percentage points.