In a closely watched tuneup for the fall congressional elections, Republicans retained a New Mexico seat held by the GOP for nearly three decades.

Heather Wilson, a former arms negotiator in the Bush administration, defeated Democrat Phil Maloof, a millionaire state senator, in a special election Tuesday for the vacant seat of five-term GOP Rep. Steve Schiff, who died of skin cancer in March.Wilson becomes the first woman from New Mexico to serve in Congress in 50 years. Her victory in the Albuquerque-area district was a setback for Democrats, now outnumbered by Republicans in the House 228-206. There is one independent.

Hillary Rodham Clinton and Tipper Gore had campaigned for Maloof in the closing days of what became the most expensive congressional campaign in New Mexico history.

"So much for Democrat dreams of wielding the gavel anytime soon," Republican National Committee Chairman Jim Nicholson said. "This victory slams the door shut on any Democrat hopes for regaining the House."

Wilson could be sworn in later this week. She will serve the rest of Schiff's term, though she has to run against Maloof again in November.