Democrats from all walks of political office are going for broke in the midterm elections on transitioning the U.S. electricity system away from fossil fuels to more quickly combat climate change.

More than 1,400 candidates running for every level of government office this November have committed to some form of a goal to mandate 100 percent clean, zero-emissions electricity in their state by 2050, according to the environmental group League of Conservation Voters.

The list includes Democratic gubernatorial candidates J.B. Pritzker in Illinois, Tony Evers in Wisconsin, Jared Polis in Colorado, Maryland’s Ben Jealous, California’s Gavin Newsom, and Gretchen Whitmer in Michigan.

It also includes first-time federal office-seekers in the House, including progressive sensation Alexandria Ocasio-Cortez in New York and Ilhan Omar in Minnesota. State legislative candidates from Idaho to North Carolina are running on “100 percent” platforms.

“Candidates recognize voters want someone with a vision,” said J.R. Tolbert, vice president of state policy at Advanced Energy Economy, a trade group representing clean energy technologies. “They want something they can respond to.”

A 100 percent carbon-free or renewable energy target has long been a slogan more than an achievable policy goal for Democrats who want to transition the power grid faster to non-emitting sources. The nation’s electricity system is already moving away from coal to natural gas, which emits half the carbon, and to a lesser extent renewables such as wind and solar that have come down in cost. But a recent United Nations report said emissions should be net-zero by midcentury to avoid the worst outcomes of climate change, heightening the urgency.

“Elections or no elections, I want folks to know we are trying to do our part to stop climate change,” said Mary Cheh, a Democrat on the D.C. Council running for re-election, who has introduced a bill that would move the district to 100 percent renewable energy by 2032. "It's not pie in the sky," she told the Washington Examiner in an interview. "We are not doing something that's wholly impossible. 100 percent renewables is quite possible.”

Some clean energy advocates welcome the lofty goals, but they worry that candidates in campaign settings are oversimplifying their solutions, and potentially deterring moderate Republicans who want to act on climate change, but may prefer a market solution to an aggressive mandate.

“The 100 percent platform distracts from more serious efforts to make progress on tangible policy outcomes,” said Shane Skelton, a former energy policy staffer for House Speaker Paul Ryan, R-Wisc.

Tolbert says he worries Democrats embracing 100 percent renewable targets could be vulnerable to criticism from Republican opponents.

For example, Walter Stapleton, the GOP gubernatorial candidate in Colorado, has repeatedly attacked Polis’ goal of 100 percent renewable energy by 2040 as “extreme” and costly.

“The last thing I want is someone staking out a strong position on advanced energy being seen as something that costs them," Tolbert said.

The other obstacle the 100 percent renewable campaign faces is proving they know what they are talking about.

Most of those running on 100 percent platforms don’t say what generating sources would qualify as renewable, or make a distinction of whether they would permit non-carbon “clean” energy sources that aren’t renewable. These include advanced nuclear reactors, or carbon, capture, and storage technologies that can collect carbon emissions from coal or natural gas plants and store it underground.

“There is a massive difference between 100 percent renewables and 100 percent clean energy,” said Noah Kaufman, an energy economist at Columbia University. “I’m not sure a lot of politicians fully grasp this distinction.”

Last year, renewable energy accounted for about 11 percent of U.S. energy consumption, and 17 percent of electricity generation, according to the Energy Information Administration.

The EIA defines renewable energy broadly to include hydropower, which is the most used zero-carbon electricity generating resource, biomass, and geothermal, along with wind and solar.

But some environmentalists have come to associate renewable energy narrowly to be wind and solar, and are pressuring politicians to agree. Deb Haaland, a Democrat running for New Mexico’s 1st Congressional District, is drawing attention for potentially being the first Native American in Congress. She also has an aggressive energy platform, calling for 100 percent renewable energy “powered completely by wind, water and sunlight.” Haaland mostly emphasizes solar power.

“Here in New Mexico, we are already experiencing increasingly severe droughts from climate change, and we have an incredible amount of sun ready to be harnessed by solar farms,” Haaland told the Washington Examiner. “It's time to move towards 100 percent renewable energy so that New Mexico, and America, can benefit from the coming wave of clean energy jobs."

Some clean energy supporters say the intermittency of wind and solar resources make it unrealistic and expensive to depend only on them for electricity until energy storage technologies are more widely adopted which would enable their use when the sun sets and wind is not blowing.

“Limiting the toolbox of low carbon technologies makes climate action more difficult and expensive,” Kaufman said.

Lawmakers in California recently recognized the limitations of a wind and solar-only approach, passing a bill this summer to require that 100 percent of the state’s electricity come from carbon-free sources by 2045 — allowing non-renewable sources to qualify.

California joined Hawaii to be the only U.S. states with 100 percent carbon-free electricity mandates required by law.

“The grown-ups in the room, the serious actors are moving to the more inclusive, broader clean energy framing,” said Rich Powell, executive director at ClearPath, a conservative clean energy group. “It's pretty fair to say the 100 percent renewables vision is at best very challenged, and economically unfeasible.”

James Smith, the Democratic nominee for governor in South Carolina, has made clean energy a core part of his campaign, and is deliberate in using that framing. On his campaign site, he highlights his work in the state legislature where he sponsored a bipartisan bill that would lift a cap on solar power.

“Because of the failures of the past in South Carolina, we are so far behind neighboring states with renewable energy,” Smith told the Washington Examiner in an interview. “I certainly believe in 100 percent renewables as a goal. But we need to make critical changes to make that a realistic goal. It’s not like a light switch.”