Environmental issues are emerging as a major factor in some key Senate races as voters show increasing concern on topics such as climate change and conservation measures.

President Trump and Senate Majority Leader Mitch McConnell (R-Ky.) are seeking to boost the electoral appeal of Sens. Steve Daines (R-Mont.) and Cory Gardner (R-Colo.) by putting their support behind legislation that permanently funds the Land and Water Conservation Fund (LWCF), which provides money to protect and conserve habitats of endangered species, develop parks and outdoor recreation sites and protect sensitive forests. 

The bill, called the Great American Outdoors Act, is moving closer to a formal Senate vote and was introduced to the House on Thursday. It has wide support in Montana and Colorado, and Trump has vowed to support it in a bid to boost Daines and Gardner as they face tough challenges from Montana Gov. Steve Bullock (D) and former Colorado Gov. John Hickenlooper (D), respectively.

Meanwhile, in Massachusetts, Sen. Ed Markey (D) is leaning hard on his environmental record, including his role in co-authoring the Green New Deal resolution with Rep. Alexandria Ocasio-Cortez (D-N.Y.), as he seeks to fend off a primary challenge from Rep. Joe Kennedy III.

The growing importance of environmental issues in these races comes as voters, particularly Democrats, express concerns about issues such as climate change. A Morning Consult poll conducted last month found that 71 percent of voters are concerned about climate change, with 38 percent responding that they are “very” concerned.

Gardner and Daines teamed up to introduce the Great American Outdoors Act, which would permanently fund the LWCF. The bill was introduced to the House on Thursday by a bipartisan group of lawmakers and appears to have a good chance of passage in both chambers. 

Democratic strategist Steve Welchert noted that Gardner needs a win on an issue that resonates in Colorado, a critical state in the battle for the Senate this fall.

“He’s got to show some bona fides on land use and water quality and public lands because it’s an area where historically Republicans don’t perform very well,” Welchert said. 

Gardner has campaigned on his support for funding the LWCF, running ads on Facebook on the issue in March and April. More than 30 percent of Colorado’s territory consists of public land, making conservation a key issue for its voters. 

Colorado College found in February that 80 percent of Western voters, including 84 percent of Montanans and 81 percent of Coloradans, said that issues involving clean water, clean air, wildlife and public lands are important in deciding whether to support a public official. For 44 percent of Western voters, it was a “primary” factor. 

Defending Colorado is a vital part of Republican plans to hold onto their 53-47 majority at a time of growing worries about their electoral prospects. Democrats need to flip three or four seats, depending on who wins the White House, to take control of the chamber and are aggressively targeting the state. 

Trump, in his annual budget proposal, had proposed slashing funding for the LWCF, which uses oil and gas revenue to fund conservation efforts, by about 97 percent. 

But Trump later called on Congress to send him a bill that fully funds the program, giving a shoutout to Daines and Gardner. 

"When I sign it into law, it will be HISTORIC for our beautiful public lands. ALL thanks to @SenCoryGardner and @SteveDaines, two GREAT Conservative Leaders!" he tweeted in March. 

Gardner spokeswoman Meghan Graf characterized the senator as a “commonsense, bipartisan politician with a record of protecting the best Colorado has to offer” in a statement, adding that he was “able to secure the President's support” for funding the LWCF. 

Gardner is expected to face Hickenlooper, though the former governor will need to first win the Democratic primary set for June 30. The seat is rated as a “toss-up” by nonpartisan prognosticator the Cook Political Report.

Hickenlooper made climate change a centerpiece of his failed presidential bid, though he faced scrutiny from the left over his perceived closeness with the fossil fuel industry. Hickenlooper has defended his efforts to regulate the sector.

Hickenlooper is also in the midst of a legal fight over a complaint from a Republican-led group that he violated state law by accepting private flights. He has strongly denied wrongdoing and said the complaint is politically motivated.

Montana is also looking like it will see a competitive Senate race after Democrats nominated a formidable candidate in Bullock, who has led Daines in some recent polling. The seat is rated as “lean Republican” by Cook.

Daines campaign spokesperson Julia Doyle told The Hill in an email that the senator’s “efforts with the President are directly responsible for the historic step we’re about to take for LWCF.”

Doyle also highlighted Daines’s work on conservation legislation in the Rocky Mountains, North Fork Lands Withdrawal Area and the Gallatin National Forest, which were ultimately approved by Congress.

Democrats, however, are looking to attack Daines on his environmental record as they look to blunt any potential positive impact from passing the Great American Outdoors Act. 

“Daines getting credit for advancing the Land and Water Conservation Fund is a total sham. It’s a clear election year play,” said Democratic strategist Barrett Kaiser, who has also worked on LWCF issues. 

“Conveniently now that Steve Daines is up for reelection you’re starting to see momentum on it in the Republican-controlled Senate,” he added, particularly referencing a bill that Daines previously introduced that advocates say would have removed certain public lands protections. 

The importance of environmental issues in Senate races extends beyond the Western states.

In liberal Massachusetts, Markey has emphasized his Green New Deal leadership and touted endorsements of environmental groups, including the progressive Sunrise Movement, as he strives to make his case ahead of his Sept. 1 primary against Kennedy. 

“Ed Markey wanted the environment to be the issue that drove the race,” said Democratic strategist Michael Goldman, who has ties to both candidates but has endorsed neither. 

Markey’s campaign manager John Walsh said that the pandemic illuminates the importance of the Green New Deal, a broad policy framework that seeks to mobilize the U.S. economy to fight climate change. 

“As the economic challenges that are clearly coming to view around the impacts of COVID, [the] Green New Deal is the solution,” Walsh said. “It is a blueprint for how to bring the economy back, to do it in a way that is smart, is green and is effective at putting people to work right away.” 

Kennedy, meanwhile, has worked on environmental inequality. In February, he co-sponsored a bill aiming to address environmental issues faced by nonwhite and low-income communities, which has not yet passed the House. 

“From the day I announced this Senate campaign, I have shown up in the communities left out of past climate debates,” the congressman told The Hill in a statement.  “From the earliest days of this pandemic, I have demanded those same neighborhoods are at the forefront of our response.”