Sen. Pat Toomey (R., Pa.) was the only senator from the Philadelphia region to vote against the plan to end the government shutdown Wednesday night.
Toomey joined 17 other Senate Republicans, including Ted Cruz of Texas and Rand Paul of Kentucky, in opposing the bipartisan plan.
He did so hours before six Republican members of the House from the Philadelphia suburbs, as well as every Democrat, voted in favor of it.
A steadfast fiscal conservative, Toomey said he voted no because the bill failed to address government spending and the debt.
"The one major redeeming aspect of this bill is that it reopens the government," he said in a statement. "But I cannot support piling hundreds of billions of dollars of debt on current and future generations of Americans without even a sliver of reform to start putting our fiscal house in order."
In light of the 81-18 vote, Toomey's stance did not endanger the deal. But it did produce a swift reaction from Pennsylvania Democrats, who within an hour of the Senate vote proclaimed that Toomey had joined the "extreme tea party" wing of the Republican Party.
"His vote tonight not only would extend the shutdown, but force the U.S. economy into default and careen global financial markets into crisis," the state party said in a news release.
The "aye" votes included Sen. Robert P. Casey Jr. (D., Pa.) and both New Jersey senators, Republican Jeffrey S. Chiesa and Democrat Robert Menendez.
"I am supporting this option because it is the only responsible course we have available at this time," Chiesa's statement said. "I am hopeful this framework will allow for serious discussions and real reforms to our government's spending problems that have led to a debt that will soon exceed $17 trillion."
When the House took its vote, six Philadelphia-area Republicans supported the deal. The sole vote against from the region was U.S. Rep. Joseph R. Pitts (R., Pa.), whose district includes parts of Chester and Lancaster Counties.
The six lawmakers, all from moderate suburban districts, had been arguing to end the shutdown.
The region's Democrats in the House all voted in favor of the plan, which had President Obama's backing.
Through aides, Republican Reps. Mike Fitzpatrick, Patrick Meehan, Jim Gerlach, and Charlie Dent of Pennsylvania, and Frank LoBiondo and Jon Runyan of New Jersey, said earlier in the day that they, too, would back the plan. They signaled their support in a joint statement released through Dent's office.
"We applaud our Senate colleagues for working together to come up with a solution," the statement said. "Now it is time for Congress to act to get the government open and avoid further roiling the markets."
The statement was signed by 16 House Republicans and 24 Democrats. Meehan released his own statement.
The Delaware County Republican said he still wanted to undo "the train wreck" of the Affordable Care Act, "but after three weeks of stalemate, it's past time for Congress to get its act together and put this crisis behind us."
In recent days, Dent and the five other area Republicans were among the first in their party to break ranks and call for ending a shutdown that has torpedoed GOP poll numbers. By the time the House voted, they were among 87 Republicans voting for the bipartisan deal to reopen the government and avoid default.
Conservatives had balked at any deal that did not force changes in Obamacare. They initially demanded a complete defunding, setting off the latest exchange of hostilities.
The six local Republicans urged less confrontational tactics. They represent districts Obama either won or narrowly lost in 2012, and lately they have faced repeated attacks from Democrats who have seized on the recent dysfunction in the House. Fitzpatrick, Runyan, and LoBiondo, in particular, are prime electoral targets in 2014, as Democrats try to take control of the chamber.
The deal approved Wednesday included only one modest change to the Affordable Care Act - requiring people to verify that their incomes are small enough to qualify for subsidies to help them buy insurance on the exchanges.
Toomey, elected in 2010, is a past president of the free-market group Club for Growth. He has had to strike a balance between appealing to his allies on the right and reaching for compromise as Pennsylvania has turned more Democratic.
This is not the first time Democrats have tried to label him extreme. In late September, he voted with Cruz and other conservatives for a shutdown-related measure. But he also warned against risking a shutdown over Obamacare, saying it was "not a tactic that's going to get us the outcome we want."