WASHINGTON — Congressman Jared Polis plans to join the crowded race for governor this week, and in doing so, the Boulder Democrat will advocate a vision for Colorado that tests how far to the left the state has shifted politically in the last decade.

In an interview with The Denver Post, the fifth-term lawmaker said his platform will focus on three initiatives: getting Colorado to use 100 percent renewable energy by 2040, ensuring parents can access free, full-day preschool or kindergarten for children age 3 and older, and encouraging companies in the state to provide stock options to employees.

“This is a campaign of big, bold ideas, and I’m trying to make them happen,” Polis said. “We want a Colorado that works for everybody.”

His entry further scrambles a contest that already lacks a clear favorite, and it all but guarantees that the 2018 race to replace Gov. John Hickenlooper will be one Colorado’s wildest elections in years. Polis’ run is notable too, given that the onetime Internet wunderkind can use his sizable fortune to fund his campaign and — if he wins — Polis would make history as the state’s first openly gay governor.

Before that happens, however, Polis will have to navigate a field that is striking in its size and depth.

One of Polis’ main rivals in the Democratic primary will be fellow congressman Ed Perlmutter, a lawmaker whom Polis has served alongside since Polis joined the House in 2009. With both Polis and Perlmutter in the race, the only House Democrat from Colorado not running for governor in 2018 is U.S. Rep. Diana DeGette of Denver.

It won’t just be them, either.

Former state Sen. Mike Johnston was one of the first Democrats to throw his hat into the ring, and he surprised many political observers by raising an eye-popping $625,000 in his first fundraising quarter. Also competing: Cary Kennedy, a former state treasurer, and businessman Noel Ginsburg.

And those are just the Democrats.

The Republican side features Doug Robinson, the nephew of Mitt Romney; George Brauchler, the prosecutor of the Aurora theater shooter; and former state legislator Victor Mitchell. State Treasurer Walker Stapleton, a distant relative of Jeb Bush, may also run, as might Kent Thiry, the head of the Denver-based dialysis giant DaVita Inc.

“The game is on, and Mr. Polis will heighten it even more,” said Floyd Ciruli, a Denver-based political consultant. “He definitely changes the complexion of the race.”

Adding to the intrigue is the nature of Polis’ candidacy. Though Polis represents Boulder, one of the most active liberal strongholds in the country, his record occasionally has conflicted with that wing of the party.

In 2015, he bucked the Sierra Club and supported a bill that would have helped clear the way for the passage of a controversial trade deal known as the Trans-Pacific Partnership. While the 12-nation accord ultimately collapsed under domestic political pressure, Polis took heat for voting in favor of giving President Barack Obama fast-track authority to approve deals such as the TPP.

“Colorado is a trade-dependent state,” Polis said of the vote.

Like Perlmutter, Polis also faces a challenge in winning support from Colorado Democrats who backed U.S. Sen. Bernie Sanders. The Vermont lawmaker beat rival Hillary Clinton in the state, but Colorado’s so-called superdelegates — comprising elected officials and party insiders such as Perlmutter and Polis — got behind Clinton at the Democratic National Convention. The decision irked Sanders supporters, and the move could haunt the two congressmen.

The fight Polis probably is best known for, however, is his 2014 battle against hydraulic fracturing — or fracking — a process in which energy companies pump water, sand and chemicals into the ground to extract oil and gas. That year, Polis led an effort to put two initiatives on the ballot that would have imposed new restrictions on fracking, including a larger buffer between homes and rigs.

The campaign had support of many environmentalists, but it terrified a number of establishment Democrats — in large part because it was seen as potentially damaging to the re-election campaigns of Hickenlooper and then-U.S. Sen. Mark Udall. The worry was that oil and gas companies would spend big to defeat Polis’ fracking measures and — as a result — more conservative voters would turn out and drag down the Democratic incumbents.

Faced with intense intraparty pressure, Polis ultimately agreed to a deal in which he would withdraw the fracking initiatives in exchange for the energy industry withdrawing two of its own. As part of the agreement, Hickenlooper also assented to the creation of a task force to make recommendations on future fracking policies.

The consequences of that 2014 showdown continue to reverberate today.

In its aftermath, Hickenlooper won a second term as governor but Udall lost to current U.S. Sen. Cory Gardner. Meanwhile, the task force led to little in the way of widespread change — a result Polis called unfortunate.

“I think the task force fell short,” Polis said.

It also may have hurt Polis’ standing among some eco-activists, though one environmentalist didn’t describe it as a significant mark.

“Some may have lingering feelings from the oil and gas initiatives a few years ago, but I don’t think it’s widespread,” said Pete Maysmith, the executive director of Conservation Colorado. “Certainly, Congressman Polis has been a longtime friend of the environment.”

Indeed, the 2014 ballot initiatives likely wouldn’t have gone far without the hundreds of thousands of dollars Polis plucked down to help advance them.

That ability — to write a check for a cause or campaign — is one reason Polis could cause headaches for his opponents.

The state has strict limits on fundraising, and those caps make it much easier for self-funding candidates to outspend their competitors. It’s a situation Polis used to his advantage in 2008, when he spent about $6 million of his own money to help win his Boulder-based House seat, according to federal records.

He said he plans to do the same this time around.

“I wouldn’t ask other people to invest in my race if I wasn’t willing to invest in it myself,” Polis said.

The ability comes from a series of internet-related ventures Polis, 42, has profited from since college — a run of success that includes online greeting cards and ProFlowers.com.

“For most people, Valentine’s Day and Mother’s Day are pleasant holidays. For me, I still have cold sweats at night because those were the most stressful times of the year,” Polis said.

The effort paid off, however, and now Polis is consistently ranked among the richest members of Congress; his net worth recently was estimated at more than $90 million.

Starting Monday, when Polis officially launches his governor’s bid, he will use that cash to help advance an agenda that is notable for its liberal ambition in a state almost evenly divided among Democrats, Republicans and independents.

He’ll need the money, too, especially if he wins the Democratic primary.

Colorado’s powerful oil and gas sector, which employs tens of thousands of workers statewide and remains a huge economic driver, likely will mobilize in a big way against both his candidacy and his proposal to get Colorado electricity providers to derive 100 percent of their power from renewable energy sources, such as wind and solar, by 2040.

The state has already required its investor-owned utilities to generate 30 percent from renewables by 2020.

“It’s going to be very hard for Polis’ ideas to resonate outside Boulder,” said Matt Dempsey, an industry consultant based in Denver.

At the same time, his other plans — to expand early childhood education and to create a state-affiliated center to encourage companies to expand stock options to their employees — could face opposition from fiscal hawks and business owners.

Polis said he’s open to ideas on how to pay for them, but not the importance of making them happen.

“There’s a lot of opportunity to do good on the state level,” he said.