New Mexico Rep. Ben Ray Luján announced Monday that he will not run for the Senate, taking one big name out of the Democratic primary mix.

“I appreciate the outpouring of support I have received while traveling around New Mexico these past few months, and my focus will continue to remain on serving the hard-working men and women of New Mexico — fighting to turn our economy around, put people back to work, and move our state forward,” he said in a statement.

Luján’s decision means Rep. Martin Heinrich is the lone top-tier candidate in the Democratic primary. However, state Auditor Hector Balderas is expected to jump into the race this week.

Democrats had hoped to avoid a competitive primary in the race to replace retiring Sen. Jeff Bingaman (D). Republicans are expected to have a competitive primary as well, with former Rep. Heather Wilson already running and Lt. Gov. John Sanchez strongly considering a bid as well.

Luján, 38, was first elected to the House alongside Heinrich in 2008. He represents northern New Mexico’s 3rd district, which includes Santa Fe, holds a leadership position in the Congressional Hispanic Caucus and is a member of the Democratic Congressional Campaign Committee’s recruiting team.