But the national political stakes became clear when the House speaker, John A. Boehner, arrived on Monday for a visit that drew a few hundred people, including residents, local dignitaries and television crews.
Mr. Boehner came to provide a spark to the struggling campaign of Jane L. Corwin, the Republican running for a vacant House seat representing New York’s 26th Congressional District, in the western part of the state. A special election scheduled for May 24 is to determine who will fill the seat left by Representative Christopher Lee. Mr. Lee resigned in February after he e-mailed a shirtless photo of himself to a woman and it appeared on the Web.
While the district is dominated by Republican voters, Ms. Corwin, a state lawmaker, has seen her lead diminish in recent weeks, as the Democratic candidate, Kathy Hochul, has repeatedly warned that older residents, a key voting group, would be hurt by a deficit-cutting plan adopted by House Republicans that calls for overhauling Medicare.
The unexpected traction that Ms. Hochul is gaining on the issue has prompted national Democrats, who were initially going to skip the race, to jump in and try to frame it as a political test of the Republican agenda in Washington.
Senator Kirsten E. Gillibrand of New York announced Monday that she, too, would head to the 26th District to campaign for Ms. Hochul, a fellow Democrat.
Mr. Boehner, appearing at a fund-raiser with Ms. Corwin on Monday, accused Democrats of engaging in political chicanery, although he did not explicitly mention the Medicare issue or take any questions from reporters on the subject.
“The Democrats,” said Mr. Boehner, Republican of Ohio, “are hoping they can steal this election and move their agenda, which is more taxes and higher spending.”
“I think,” he added, “that all of you being here today shows that people in western New York have a different agenda.”
Mr. Boehner also used the opportunity to note that Ms. Corwin was the “only conservative” in the race, a remark that, aides said, was aimed at Jack Davis, a former Democrat who opted to run on the Tea Party line after failing to win the Republican nomination for Congress.
In recent weeks, Republicans have become increasingly concerned that Mr. Davis is drawing Republican support from Ms. Corwin and have concluded that the key to victory lies in raising doubts among voters about Mr. Davis’s conservative credentials.
Ms. Corwin’s campaign is running a television advertisement in the region describing Mr. Davis as a Democrat and pointing out his history of supporting Democrats, including Representative Nancy Pelosi of California, the Democratic leader in the House and a bête noire of the right.
Mr. Boehner’s visit was welcomed by local Republicans, worried about losing a seat that their party has held for decades.
“Anytime there’s a race this tight, especially a special election, you have to bring out the firepower,” Laurie Frey, a Republican from Clarence, said.
“I’m a little worried,” Ms. Frey added. “But it’s a heavy Republican district, and I think we will pull through in the end.”
Democrats sought to make the most, politically, of the Boehner visit. Ms. Hochul gathered with a few dozen supporters at her campaign headquarters, where she continued to hammer away at Ms. Corwin, who has steadfastly supported the Republican Medicare plan.
Ms. Hochul said that the plan would destroy Medicare and that voters in the district had an opportunity, by electing her, to send that message to Congressional Republicans.
“This election presents the clearest choice for this nation,” Ms. Hochul said. “We can alter the national debate with one election.”
Mr. Boehner, on his visit, took time to meet with Families of Continental Flight 3407, a local group that has been pushing for stricter air safety standards since a deadly plane crash near Buffalo two years ago.
Ms. Corwin’s campaign, revealing the vigor with which the race was being fought, made a point of telling reporters that she had asked Mr. Boehner to meet with the group.
Mr. Boehner’s aides said he promised the group that he would try to address their concerns.
Stretching from the western suburbs of Rochester to the villages and towns northeast of Buffalo, the 26th District has 30,000 more registered Republicans than Democrats.
The race did not initially draw much attention outside of western New York, largely because leaders of both parties expected that Republicans would be able to keep the seat. But Ms. Hochul, after seizing on Medicare, has shown strength in polls. Her aides said she would pound away on the issue until Election Day.
Michael D. Regan contributed reporting from Clarence.