Sen. Jeff Bingaman (D-N.M.) said yesterday he would seek a fifth term in 2006, making it unlikely that Republicans can pick up the seat.

Still, a competitive race may be in the offing. If Rep. Heather Wilson (R-N.M.) were to challenge the senator, the National Republican Senatorial Committee (NRSC) would spend “ample” time and money electing her, a GOP source said.

Wilson could not be reached for comment.

Bingaman won his last race with 62 percent of the vote versus 38 percent for Republican Bill Redmond. Bingaman spent nearly $2.6 million, compared to his rival’s $640,000.

That was an improvement from 1994, when Bingaman won 54 percent of the vote compared to 46 percent for the Republican.

A spokeswoman for Bingaman released a statement yesterday afternoon in which the senator said: “While we have made progress in education, heathcare and job growth, there is more work to be done on these and other challenges facing New Mexico. I am committed to continuing my strong advocacy. ...”

It is unclear, for now, which way New Mexico leans. President Bush narrowly carried New Mexico last year, but Gov. Bill Richardson, elected in 2002 with 55 percent of the vote compared to 39 percent for his rival, is a Democrat, and Al Gore won the state in 2000, albeit barely. New Mexico’s senior senator, Pete Domenici, is Republican.

Brian Nick, the NRSC spokesman, would not rule out a competitive race. “We’re very hopeful that a quality candidate comes forward to make this a competitive race,” Nick said. “There are a number of reasons why this could be a sleeper for Republicans.”