Gov. Tom Corbett is inclined to sign the amended bill, a spokesman said.

"I can't believe that Harrisburg would give an exemption to Washington County but not Allegheny," fumed Rich Fitzgerald, Democratic nominee for Allegheny County executive and a foe of reassessments. "Allegheny County's last reassessment was in the last 10 years. Washington County's, I think, was 30-some years."

Washington County last reassessed property in 1981.

"Allegheny County residents are going to have massive tax increases," Mr. Fitzgerald said. "Why aren't our [legislators] fighting for Allegheny County property owners? I don't understand."

Mr. Pippy said any suggestion that Republican senators were trying to stick it to Allegheny County's Democratic leadership "is baloney."

"It wasn't about, 'We don't want to help these guys,' " Mr. Pippy said. "It was like, 'There's no way we can do that.' "

Mr. White said he wanted the moratorium to remain statewide but had no choice but to vote for the narrowed bill to stall Washington County's process. Sen. Wayne Fontana, D-Brookline, took the same position.

In Washington County, two school districts sued to force a reassessment. In Allegheny County, it was a group of residents that launched the court fight.

County leaders often resist reassessments, but they aren't necessarily a political third rail, Mr. Hill said.

"It is survivable, politically," he said, pointing to recent reassessments in Dauphin, Cumberland, Bradford and other counties that were then followed by re-election of their commissioners.

Counties, he added, want the state to solve some thorny issues, such as whether they can assess commercial, residential and agricultural property in different ways and how they should address the effect of neighborhood desirability on a property's value.

"Everybody says, 'Oh, the Legislature hasn't acted in 40 years, they haven't done anything about it,'" Mr. White said. He said things could be different next year. "This issue is now on the front burner."