Rep. Tim Ryan, R-Ohio, talks with reporters outside the House Democrats' leadership elections in Longworth Building on November 29, 2018.

Rep. Tim Ryan, an Ohio Democrat best known for trying to topple Nancy Pelosi as House Democratic leader, will run for president, he announced Thursday.

The congressman, who has served since 2003, enters a crowded Democratic presidential field jockeying to take on President Donald Trump next year. More than a dozen Democrats have already declared their candidacy.

Ryan, whose challenge to Pelosi from the center failed in 2016, will likely position himself as a moderate option in the field. The congressman represents a district with a large auto-industry presence. He will likely tout his efforts to boost manufacturing and working-class Americans in a challenge to Trump's outreach to blue-collar workers.

"When our local GM factory was shutdown last Thanksgiving, I got a call from my daughter who was consoling her friend whose father was an auto worker and was just laid off. My daughter said to me, with tears in her voice, 'You have to do something,'" reads his campaign website launched Thursday. "That's why I am running for President. It's time to do something."

He also cites issues such as health care, education and veterans' care on his campaign website.

Ryan faces an uphill climb in a field that already contains six senators and two current and former governors — and which could soon include a former vice president. Still, the 45-year-old congressman could see his background and experience in swing state Ohio as an asset, especially after Sen. Sherrod Brown, D-Ohio, declined to run for president.

In a statement, Republican National Committee Communications Director Michael Ahrens called Ryan a "backbencher who has no chance of becoming president." Ahrens criticized Ryan for his support for "Medicare for All," a government-run health care system that would cover all Americans.

Trump won Ohio state comfortably in 2016, in part by pledging to renegotiate trade deals and boost the auto industry in the state. Ryan represents Lordstown, where General Motors shut down a manufacturing plant last month. The community will lose about 1,300 jobs, though about 417 of those will transfer to other GM plants.

In November, Ryan said Trump "has been asleep at the switch and owes this community an explanation" for the facility closure.

Trump has recently criticized GM and pushed the company to reopen the Lordstown plant.

Every presidential election winner has carried Ohio since 1964.

Subscribe to CNBC on YouTube.