WASHINGTON – Democrats are attacking one of Sen. Pat Toomey's strengths, accusing him of quietly backing away from his high-profile support for expanding background checks for gun purchases, a stand that has won him bipartisan praise and could bolster his re-election appeal.

Two of the Democrats running to unseat Toomey, a Republican, pointed to a recent online post by a gun-owners' group claiming the senator's office made assurances he would not make another push for his background check bill, co-sponsored with Sen. Joe Manchin (D., W.Va.) after the 2012 Sandy Hook school shooting in Connecticut.

A Toomey spokeswoman denied that anyone in his office had told the group that the bill would not be re-introduced. He is "100% committed to expanding background checks to keep guns out of the hands of criminals and the mentally ill," E.R. Anderson wrote in a statement.

The senator as recently as June publicly reiterated his support for tougher background checks as he was honored by family members of Sandy Hook victims. "I'm convinced that more background checks will save lives," he said in a late June speech at a gala.

He said then, as he has for years, that he was looking for ways to advance his bill, or a part of it, but did not see a viable path forward or any immediate hope for success. He has not re-introduced the bill or any new version.

But Democrats say the gun rights groups post shows that Toomey is not a committed ally on new gun laws.

"Pat Toomey was caught red-handed telling certain groups one thing, and telling Pennsylvanians something completely different," said Mike Mikus, a spokesman for Democratic candidate Katie McGinty.

"Do you want a warrior who is beside you all the time, or a guy who deserts after one lost battle?" asked another Democrat in the race, former Congressman and admiral Joe Sestak.

As he faces a difficult re-election in a blue-leaning state, the high-profile, bipartisan work on the background check bill is expected to be a key illustration of Toomey's appeal to swing voters. But the flap illustrates the balancing act required as he also tries to retain conservative support.

A leading Pennsylvania advocate for tougher gun laws said she puts her stock in Toomey's public comments.

"We're not going to get all worked up because some group claims they got a promise that the (senator's) office is disavowing," said Shira Goodman, executive director of CeaseFirePA. "Actual votes and actions are more important than rumors."

Goodman added, though, that she will continue to watch how Toomey votes on other bills related to guns.

The gun-owners' group, Pennsylvanians for Self Protection, wrote on its web site Sept. 9 that it had "received positive responses to our request that the Toomey-Manchin anti-gun legislation or any similar bills not be reintroduced," and therefore cancelled rallies targeting Toomey office around Pennsylvania on Sept. 13.

The group's legislative director, Tom Campione, told Politico that he had received assurances from Toomey's state director, Bob DeSousa. Anderson, Toomey's spokeswoman, denied that.

Campione later told the Allentown Morning-Call he had heard from multiple sources that there was "no longer any plan to reintroduce" the background check bill. He did not respond to messages from the Inquirer.

A third Democrat in the race, Braddock Mayor John Fetterman, dismissed the controversy.

"Show me a common sense gun reform law that would have kept seven of the nine murder dates from being tattooed on my arm and I will support it," Fetterman wrote in an e-mail. "Otherwise this is just political theater -- pretending that people want to do something about it."

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