This district should have been an easy Republican win. Registered Republicans substantially outnumber registered Democrats in the 26th, and  Christopher Lee, the GOP congressman who resigned his seat after — I use the New York Times’ nicely restrained language here — “he e-mailed a woman a shirtless photo of himself that appeared on the Web,” won in 2010 with almost 74 percent of the vote.

But Democrat Kathleen C. Hochul has made a race of it by targeting the Medicare privatization plan in Rep. Paul Ryan’s budget that was adopted by the House Republican majority. Hochul is further helped by the independent Tea Party candidacy of Jack Davis, a conservative former Democrat who is taking is votes away from Republican Corwin. This Hochul ad makes the clear case for the Democrats’ core argument — that Ryan would cut Medicare to protect tax cuts for the rich. 

The latest poll in the race comes from the Public Policy Institute. Sponsored by the Service Employees International Union and the liberal Daily Kos Web site, it gives Hochul 35 percent, Corwin 31 percent, Davis 24 percent and Green Party candidate Ian Murphy 2 percent. Yes, the poll is from Democratic-leaning sources, but Boehner’s visit shows that Republicans are worried that it accurately captures the dangers in this race for the GOP.

If there was any doubt that the Medicare proposal and national issues are hurting Corwin, consider these comments by Erie County Republican Chairman Nicholas A. Langworthy, reported by the Buffalo News.

“Some will try to make this a national narrative — a referendum on the president and Congress,” Langworthy said. “This is about Western New York values, and it’s about lower taxes and greater personal responsibility.” In other words: The national narrative is hurting the GOP, and shrewd Republicans such as Langworthy want the race to be about something else.

 Several caveats: The significance of any given special election is almost always exaggerated. Hochul still has to be rated the underdog, since Republicans have a couple of weeks to pound down Davis’s third-party vote and move a share of his supporters to Corwin.

 Nonetheless, this race is a warning to Republicans about the potency of the Medicare issue and the related matter of the party’s resistance to any tax increases, even on wealthy. And for those of us who see the House Republican majority as vulnerable in 2012, a Hochul victory would suggest that the Tea Party/conservative surge peaked in 2010 and that we are entering a new political phase — not so much a clear progressive surge as a reaction against conservative overreaching. Keep an eye on the 26th.