U.S. Sen. Pete Domenici has endorsed his former aide Marco Gonzales in the contested Republican primary in the 3rd Congressional District.

However, Domenici, in a television interview Friday, said he most likely won't endorse in the hotly contested GOP primary for the U.S. Senate seat Domenici is vacating. This decision can be seen as a blow to U.S. Rep. Heather Wilson, who has been viewed as Domenici's protégé for the past decade. In a 1998 special election, Domenici gave Wilson a boost by endorsing her in her first run for Congress during the Republican primary.

Now she is running against U.S. Rep. Steve Pearce in the primary.

In a postcard to Republicans in the 3rd Congressional District, Domenici wrote, "I have known and been friends with Marco for over 20 years. Marco started his public service career by serving as my legislative assistant while attending college and law school at night.

"I have seen firsthand Marco's dedication and commitment to New Mexico and have confidence in his ability to effectively represent the third district — from day one."

Gonzales is running against Rio Rancho contractor Dan East in the primary for the seat currently held by Democratic Rep. Tom Udall, who is running for Senate. Any Republican candidate is considered a long shot in the heavily Democratic district. Six Democrats are competing for the seat.

Domenici, appearing on KNME's In Focus, said of the Wilson/Pearce race, "I've chosen to let them do this on their own and see what the Republican electorate (comes) up with. The two candidates have truly put forth major effort, and I think the electorate knows who they are and how they differ and I think maybe I should leave that alone."

He left the door slightly open to changing his mind before the June primary. "Now, if something should happen untoward, where I think something was taken advantage of, I may change my mind, but that's pretty remote at this time."

Domenici denied speculation that he's working for Wilson "behind the scenes."

A campaign spokeswoman said Wilson had no comment on Domenici's decision.

Contact Steve Terrell at 986-3037 or sterrell@sfnewmexican.com.