It is not often that a political party puts more than $750,000 behind a candidate in a high-profile Congressional race, only to see the intended beneficiary endorse the opposition.

But that is exactly what happened in the race for New York’s 23rd District, a convoluted contest that turned into an Election Day disaster for the National Republican Congressional Committee.

The initial backing of Assemblywoman Dede Scozzafava in a solidly Republican district cost the House Republicans’ campaign arm a significant amount of cash, considering that she bowed out of the race under conservative pressure just days before the election. Then Ms. Scozzafava publicly threw her support behind Bill Owens, the eventual winner, who was sworn in Friday as the 258th Democrat in the House and will be a crucial vote in the health care debate.

While the traditional view among Congressional campaign veterans is that special House elections like the one in New York last Tuesday are given political significance beyond their true import, this one had some notable fallout.