New Mexico’s 1st district, a battleground for more than a decade, is in danger of sliding off the radar for national Republicans in 2012.

All eyes in Albuquerque are on a potentially nasty Democratic primary between three well-financed current or former elected officials. Given its recent voting history, a competitive open-seat race could still develop before November, but at this point Republicans view the race to replace Rep. Martin Heinrich (D) as an uphill climb.

“It doesn’t look like the Republicans are as positioned to put up as big of a fight for that seat as they have in the past, and that’s a pretty dramatic development,” said Joe Monahan, a plugged-in independent political analyst in New Mexico. “You need a heavyweight Republican in this district now more than ever because the district has just gotten more blue.”

The filing deadline came and went last week with no last-minute entrance from a big-name Republican. The GOP took a hit last month when 2010 nominee Jon Barela opted against running again and Lt. Gov. John Sanchez — who just dropped out of the Senate race — also chose to sit it out.

Three candidates will be on both June 5 primary ballots, and the Democratic nominee will likely emerge as the frontrunner heading into November.

Former Albuquerque Mayor Marty Chavez, state Sen. Eric Griego and Bernalillo County Commissioner Michelle Lujan Grisham are vying to keep Heinrich’s seat in Democratic hands. All three reported more than $200,000 each in cash on hand at the end of December.

“You’ve got three very different candidates,” one Democratic strategist said. “I think it’s going to get dirty, and I do think it is going to be close.”

The Democratic and Republican House campaign committees spent more than $1.5 million combined in the district in 2010, when Heinrich survived a disastrous year for Democrats with a 4-point victory.

Former Rep. Heather Wilson (R), who is also running for Senate, held the seat for five terms. Wilson’s moderate voting record and political acumen helped her win six elections — including a 1998 special — in the Democratic-trending district without ever taking more than 55 percent of the vote.

Redistricting did nothing to change the Democratic partisan advantage. The new map, drawn by the courts, hardly moved the lines at all — President Barack Obama still would have carried the district with 60 percent of the vote, Democrats hold a 15-point registration advantage and the district has a 44 percent Latino voting-age population.

Stephen Clermont, a Democratic pollster who has worked extensively in New Mexico, said the district, won by a Republican in 2006 and a Democrat in 2008, is no longer viewed by the parties as essential to winning the House majority.

“The GOP can lose this seat again and still maintain House control,” Clermont said. “Winning it will be a luxury for them. It is not a bellwether anymore.”

Gov. Susana Martinez (R) carried the district in 2010, Clermont noted, but a presidential year is different.

“It should be considered Democratic-leaning because the Democratic and Hispanic voters in the South Valley, Valencia County are more likely to turn out than in gubernatorial years,” he said.

Albuquerque City Councilor Dan Lewis, former state Rep. Janice Arnold-Jones and retired Army Sgt. Gary Smith are hoping to flip the seat back to Republicans.

Lewis was sitting on the largest war chest of the three at of the end of the year, with $102,000, and was rewarded by the National Republican Congressional Committee on Thursday by advancing to the “On the Radar” step of its Young Guns program, which demands candidates reach district-specific fundraising and organizational benchmarks. His progression there will offer an indication of whether the NRCC views him as a strong candidate.

Bernalillo County GOP Executive Director Steve Kush remains bullish on his party’s chances of winning the district with one of their three candidates.

“It’s a competitive primary, and quite frankly I think we’re going to have a very strong nominee coming out of this,” Kush said.

The Democrats are all taking different angles and carving out a base in the primary electorate.

Chavez, a centrist, is the most well-known and has a record of job creation that he touts on the trail. He was just endorsed by President Bill Clinton and has a well-organized campaign run by Alan Packman, who managed Heinrich’s re-election. Packman said Chavez has the experience necessary to hit the ground running in January 2013.

“This is important because New Mexicans need someone in Congress who can deliver results,” Packman said. “Marty has shown the kind of toughness you need to get things done in Washington.”

Griego is politically savvy and has the backing of top labor, liberal and environmental groups including the American Federation of State, County and Municipal Employees; the League of Conservation Voters; and Reps. Raúl Grijalva (Ariz.) and Keith Ellison (Minn.), co-chairmen the Congressional Progressive Caucus. Griego campaign manager Ed Yoon said Griego’s endorsements will translate to boots on the ground and a second-to-none grass-roots operation.

“I would argue it should be the hottest, most-watched Democratic race in the country,” Yoon said. “So the question is … what kind of a Democrat do we want to nominate for the general? The clear progressive is Eric Griego.”

Grisham got a big boost recently with an endorsement from EMILY’s List, which backs Democratic women candidates who support abortion rights and helps funnel donations and mobilize women voters. Grisham, a former secretary of the state Department of Health, was the last to enter the race but has spent little and has the most money with $278,000.

“I’ve never seen a candidate as driven as Michelle to do what she needs to win the race,” Grisham campaign manager James Henry said. “She’s a relentless worker. That’s how we’re going to win the thing.”