Newly minted Democratic Governors Association Chair Jay Inslee is staring out at a sea of red as he looks ahead to the governors’ races in 36 states this November.

The Washington state governor and others at the DGA are up against steep odds. Across the country there are currently 33 Republican governors, compared to just 16 Democrats (plus a lone independent, Alaska Gov. Bill Walker). Of these, Democrats are especially zeroing in on 13 in 2018.

This year’s midterms will be a pivotal test for Democrats. With an increasingly embattled Republican Party and an energized Democratic base, the political winds are looking favorable for them. Still, Inslee and others at the DGA recognize they have a lot of work to do to flip the seats.

The midterms will also have serious consequences for the future of the US House; whichever party wins more state legislative and governors’ seats will have the chance to influence legislative redistricting in 2020, when new congressional voting districts will be redrawn. Republicans have benefited from gerrymandering in the past, and if Democrats want to stop or change Republican redistricting, they must do well in 2018.

The high stakes are not lost on Inslee.

“This is a moment that’s a once-in-a-50-year opportunity, and it calls for maximum effort,” he said in a recent interview with Vox.

How the map is shaping up

Out of the 36 total governors’ races this year, 26 are held by Republicans. And of that number, 13 are in states that President Barack Obama won in previous presidential cycles. That fact alone has Democrats feeling confident. Election Day 2017 was also an encouraging sign; they were able to hold on to the Virginia governor’s seat and flip the one in New Jersey previously held by Republican Chris Christie.

“It just is a huge, wide-open playing field,” said Elisabeth Pearson, executive director of the Democratic Governors Association.

States whose term-limited Republican governors are stepping down already have a very crowded slate of Democratic candidates vying for the primary. As Michigan Gov. Rick Snyder prepares to depart, seven Democrats have so far filed to run, with the number expected to grow (the Republican field in Michigan is similarly crowded). There are already nine Democratic candidates running in Maine, as controversial Republican Gov. Paul LePage’s term is up this year. And in New Mexico, there are four candidates running to replace Republican Gov. Susana Martinez.

Even with so many candidates running, some names have already risen to the top. In Maine, Democrat and current Attorney General Janet Mills is seen as the frontrunner. Mills is a longtime legislator and is known for standing up to LePage in many political fights, on issues ranging from health care to declining to sue the federal government at the LePage administration’s request.

Two other female candidates, former Michigan state Senate Minority Leader Gretchen Whitmer and Rep. Michelle Lujan Grisham of New Mexico, are also leading the pack in their respective states. Whitmer has been outspoken on Michigan issues, including the state’s opioid epidemic and the Flint water crisis. Lujan Grisham is the chair of the Congressional Hispanic Caucus in the US House and has raised more than $1 million in her race so far.

Incumbent governors are usually more difficult to challenge, but one Republican governor the DGA feels confident they can unseat is Bruce Rauner of Illinois, who is embattled and unpopular within his own party. (Rauner is also likely to face a primary challenge this year.)

“We were always going to be on the offense this cycle,” Pearson said. “We’re really excited about the cycle; it is a big map, and we’re going to try to keep it as big as possible.”

Democrats also have incumbent governors in seats they’re defending, including in Connecticut, Pennsylvania, and Rhode Island.

DGA officials are feeling optimistic after Alabama voters sent Democrat Doug Jones to the Senate in December, showing in part that Republicans are torn between establishment candidates and hardline conservatives like Roy Moore, who lost to Jones amid a sexual misconduct scandal. That helped open up a path for Jones, the first Democrat Alabamians have sent to the Senate in 25 years.

“What they showed us is that Republicans are extremely divided,” Pearson said. “That division and that problem is going to continue to be a factor.”

Pearson said the DGA is looking for Democratic candidates who can both appeal to the party’s left-wing base and capture independents disenchanted with the Republican Party under Trump. That could be a tall order in a Democratic Party whose base is shifting leftward, but Pearson said she is feeling optimistic.

“We can do both, and we have to do both,” she said.

Inslee says the Democratic Party is trying to course-correct an electoral formula that focused on the biggest races for the White House and Congress. That strategy has left them vulnerable in the states. Republicans have been able to capitalize on that, building formidable majorities in state legislatures races over the course of the 2010 and 2014 midterms. In addition to the 33 Republican governors in office, Republicans currently control 66 out of 99 state legislative chambers in the United States.

“For too long, the national team has just focused on Washington, DC,” Inslee said. “The Democratic team has finally realized we have to build infrastructure in state and local communities.”

Gerrymandering is a huge factor

Though there’s often more attention to US House and Senate races during the midterms, governors’ races are especially important in 2018, with consequences for years to come.

That’s in large part due to the issue of gerrymandering, the act of redrawing legislative districts in individual states to benefit a particular political party. The 2018 midterms will be hugely consequential because they’re the elections before the 2020 census, when voting districts will be redrawn. Redistricting happens every 10 years to reflect population changes.

In the majority of states, redistricting is done by state legislatures, meaning whichever party is in charge gets to draw the lines. But in most states, governors also have the power to veto the maps. The last time voting districts were redrawn was the 2010 census year, right as Republicans made huge gains in the 2010 midterms. That meant Republicans got the electoral advantage to redraw the maps, and they took it.

Republicans in states like Wisconsin, Texas, and North Carolina drew districts that diluted the representation of packed, urban (and generally more liberal) cities and give more representation to more conservative, rural areas. Partisan gerrymandering is being challenged in the US Supreme Court, with a ruling to be issued later this year.

The 2010 redistricting has already given Republicans the upper hand, politically. A 2017 report by the Brennan Center for Justice at the New York University School of Law found that, due to the 2010 redistricting, Republicans gave themselves a 16- to 17-seat advantage in the House of Representatives that will be difficult for Democrats to overcome.

“People don’t have choice with their congressmen right now,” Inslee said. “It’s extremely important to prevent the gerrymandering that’s captured the US House of Representatives.”

That brings us up to 2018, when Democrats are staring down their last big chance before the 2020 census to change the calculus.

As Vox’s Andrew Prokop recently wrote:

Indeed, in 34 states, the governor who will be in office for the next redistricting will be elected this year (two more were just elected in 2017). And in 30 states, half or more of state senators whose terms extend through the next redistricting will be elected this year. (Most state House members, meanwhile, serve two-year terms and will be elected in 2020.) The upshot is that if Democrats want to reverse GOP gerrymanders — and perhaps get the opportunity to do some gerrymandering of their own — they can’t afford to sit around and wait for 2020. They need to make big gains in the states this year. The stakes are high, and the consequences will be felt for a very long while indeed.

Blue states can help set up a whole new set of progressive laboratories

There’s another key reason the DGA wants to help get more Democratic governors elected. With Washington controlled by the GOP, more Democrats in control of states means more progressive state policies.

The exact opposite is true in much of America right now, because of Republican dominance in state legislatures and governors’ mansions. Legislatures and governors from Texas to Ohio to New Hampshire have passed legislation to restrict abortion access, loosened gun laws, and tightened voting requirements.

At least on the West Coast, the tide is turning in the other direction. Inslee is at the head of one of the nation’s most progressive states, and he just got a boost as the Washington state Senate flipped from Republican to Democrat in a special election in November 2017. Washington was already seen as a progressive state, but the fact that Democrats regained a majority in both the legislative and executive branch had ripple effects up and down the West Coast.

With Washington’s state Senate flipping, Democrats officially control West Coast politics. Inslee and other Democratic governors in Oregon and California have formed a so-called “blue wall.”

With Democrats dominant on the West Coast, they can aggressively pursue progressive policies, including taxing carbon and other climate measures, as well as potential moves on gun control, contraception, and abortion access.

That’s a big reason why more Democrats are turning their attention outward in 2017 and 2018, trying to influence policy in the states.

“It’s the only place we can make progress in the near term,” Inslee said. “Governors cannot be stopped by Donald Trump. He cannot stop me from having a clean energy fund; he can’t stop us from having the best paid family leave policy. We’ve done all these things. He cannot stop us.”

Correction: The attorney general of Maine is Janet Mills.