The conservative group American Crossroads took out a major, six-figure ad buy to push Republican Jane Corwin across the finish line in the special election in New York's 26th congressional district.

American Crossroads said it had purchased $350,000 worth of media in the Buffalo and Rochester market ahead of next Tuesday, May 24's special election to fill former Rep. Chris Lee's (R-N.Y.) seat.

Corwin is locked in a tight, three-way race between Democrat Kathy Hochul and Jack Davis, a former Democrat-turned-Tea Party member.

Democrats with a close eye on the race say the ad buy is closer to $640,000.

“This race has become artificially competitive because liberal Democrat Jack Davis is now trying to pass himself off as a conservative while the other liberal Democrat, Katie Hochul, is benefiting from his trick,” said American Crossroads communications director Jonathan Collegio. “This ad buy seeks to expose the Democrat trick for what it is.”

Republicans are hoping to avoid the fiasco that plagued them in 2009, when Republican nominee Dede Scozzafava, who eventually withdrew, split votes with Conservative Party nominee Doug Hoffman in a special election to fill a GOP seat. Democrat bill Owens eventually won in that race, and retains the seat in Congress.

Polls have shown the race is tight, and House Speaker John Boehner (R-Ohio) was in the district on Monday to help stump for Corwin.

House Majority PAC, one of the Democratic groups that operates similarly to Crossroads, called the ad buy a sign of panic.

"John Boehner, Karl Rove, and the Right are clearly in full panic mode in what should have been a slam dunk for them in the special election in upstate New York. House Republicans’ reckless budget that guts Medicare and protects $40 billion in giveaways to Big Oil has put this heavily Republican seat in play," said Ryan Rudominer, a spokesman for the PAC.