New Mexico’s Senate race has turned into a key test of political strength for the environmental movement, which is spending heavily to block former-Rep. Heather Wilson's (R-N.M) bid. 

The battle, which pits Rep. Martin HeinrichMartin Trevor HeinrichDem senators unveil expanded public option for health insurance Senators introduced revised version of election cyber bill Senate Intel releases summary of election security report MORE (D-N.M.) against Wilson, has already seen $1.5 million spent by a coalition of green groups attacking her record on energy and the environment. That money has matched the spending by GOP-affiliated groups backing Wilson. 

“He's already been a leader and champion on protecting our natural resources and fighting for green energy jobs,” said Jeff Gohringer of the League of Conservation Voters (LCV), one of the groups backing Heinrich and funding the anti-Wilson ad campaign. 

“When you look at that and contrast that with Heather Wilson the differences are clear on this. She has a horrible record on this and has accepted more than $640,000 from oil and gas lobbyists,” Gohringer said.

Wilson, for her part, hasn't shied away from the fight, blasting Heinrich as "out on the extreme of his own party" and promising to hit the longtime environmental advocate on energy issues she says are hurting job growth.

At a Thursday event in Washington D.C., she attacked Heinrich for not supporting the Keystone XL oil sands pipeline and criticized him for supporting the climate change legislation known as "cap and trade," arguing it would have been a major tax increase and further burden on an already weak economy.

“New Mexico is one of the top energy-producing states in the nation,” Wilson said. “On this issue particularly, Congressman Heinrich is way out on the extreme of his own party.”

Heinrich’s spokeswoman said his campaign was mostly focused on jobs and the economy, but that he was proud of his environmental record. 

Before he was in Congress Heinrich served under then-Gov. Bill Richardson (D) as the state’s natural resources trustee and was a leader in the fight to keep oil and gas developers out of the Ojito Wilderness in New Mexico.

As a congressman, he introduced legislation to expand green energy development projects on federal lands.

Wilson has long fought for more drilling and opposed government support of renewable energy development. She was also a key supporter in the House of former President George W. Bush’s push to expand drilling in the Arctic National Wildlife Refuge in Alaska.

Those votes made her a top target of the LCV, which named her on multiple occasions to its “Dirty Dozen” list of lawmakers, who oppose their positions on green issues. 

Along with Defenders of Wildlife, the Sierra Club, the National Wildlife Federation and the Natural Resources Defense Council Action Fund, the LCV has spent $1.5 million in ads accusing Wilson of voting against New Mexico families and in favor of polluters.

“Emma knows not to talk to strangers. She knows how to ‘just say no.’ But Emma doesn't know about MTBE. Or that the toxin may be in her drinking water,” one ad’s narrator says as video of a young girl at school plays. “Emma doesn't know, but Heather Wilson did, when she voted to let oil companies off the hook and took their money. Who's Wilson With? Not Emma.”

 Wilson’s campaign has pushed back against the attacks, claiming that Heinrich is pushing for greater regulation that will deter job growth.

"Environmental extremists are spending millions of dollars to falsely attack Heather because her opponent, Congressman Heinrich, used to lobby for them, and they know he supports their job-killing agenda,” said spokesman Chris Sanchez. “He's too extreme for New Mexico."

New Mexico voters can expect more of that back-and-forth in coming months. Gohringer declined to talk specifics about what his group plans to spend, but made it clear they’d stay involved.

“We're certainly committed to the race and making sure Martin Heinrich is sent to the U.S. Senate,” he said.