Washington Gov. Jay Inslee is dropping out of the 2020 Democratic presidential race, he announced Wednesday night on MSNBC's "The Rachel Maddow Show."

"It's become clear that I'm not going to be carrying the ball. I'm not going to be the president, so I'm withdrawing tonight from the race," he told Maddow, vowing he'd help keep the other 2020 candidates focused on issue of climate change, the centerpiece of his campaign. "I've been fighting climate change for 25 years, and I've never been so confident of the ability of America now to reach critical mass to move the ball."

Inslee sent an email to supporters on Thursday announcing that he will run for a third term as governor instead.

"I want to continue to stand with you in opposing Donald Trump and rejecting his hurtful and divisive agenda, while strengthening and enhancing Washington state's role as a progressive beacon for the nation," he wrote.

Inslee's presidential campaign was bookended with pleas to take climate change seriously.

"This is our moment to put the greatest threat to our existence, to our economy, to our health, at the very top of the nation's agenda," Inslee said in March at his campaign's kickoff event in Seattle.

Inslee put out a detailed 10-year plan on how he'd move the country to clean energy, spurring other candidates to put out their own plans. Butting heads with the Democratic National Committee, or DNC, he demanded that the organization hold a debate focused on climate change.

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The DNC rebuffed his pleas in June, but CNN announced soon after that it would hold a town hall on the issue with the candidates in September. Inslee, however, did not meet the polling criteria the network used for the event — a minimum of 2 percent in four DNC-recognized polls — and was not on the list of attendees the network announced on Tuesday.

While Inslee said Monday that he had reached the 130,000-donation threshold for the next debate in September, his lack of qualifying polls likely would have kept him from the debate stage, as well.

He told Maddow he hopes other candidates can use his climate plan, which he said has been called "the gold standard."

He declined to throw support behind another candidate on Wednesday but said he would endorse the Democratic nominee, "no matter who it is."

Other 2020 candidates were quick to praise his efforts.

"Thank you @JayInslee for fighting every day to make sure that climate change remains a primary focus of this election. Climate change is real and it's a crisis—and I will keep fighting alongside you to take bold action before it is too late," Sen. Elizabeth Warren of Massachusetts tweeted.

Congratulations to @JayInslee on his impactful campaign to bring the climate crisis to the forefront of the national conversation. There is no more important issue facing humanity. Together we will work to pass a Green New Deal and create millions of jobs. — Bernie Sanders (@BernieSanders) August 22, 2019

"Few leaders have done more to shine a light on the climate crisis than @JayInslee," Sen. Kamala Harris of California tweeted. "His voice will be missed in this primary but I know he will continue this fight."

Inslee is the third major candidate in the sprawling field to exit the race after Rep. Eric Swalwell of California and former Colorado Gov. John Hickenlooper.