Editor's note: This story has been updated with comments from Marchant and potential candidates for his seat.

WASHINGTON — U.S. Rep. Kenny Marchant will not seek reelection in 2020.

He is the fourth member of the Texas delegation to announce his retirement in recent days.

“I am looking forward to finishing out my term and then returning to Texas to start a new chapter," Marchant said in a statement. “For the last 40 years, I have served my fellow North Texans, starting in local government as the Mayor and as a city council member of Carrollton, then to Austin as a 9-term State Representative, and then on to serving today in Washington, DC.

"What a wonderful opportunity it has been to serve them, and I want to thank them for trusting in me," he added.

Marchant, who was elected to Congress in 2004, is a founding member of the House Tea Party Caucus. He represents Texas’ 24th Congressional District, which spans the northern suburbs of Fort Worth and Dallas. The district has historically been reliably red, but Marchant’s margins of victory have grown thinner in recent elections. In 2016, he won by a comfortable two-digit margin. Last year, Marchant squeaked by with a 3 point win over Democrat Jan McDowell.

A number of candidates have already lined up to run for his seat. On the Democratic side, 2018 nominee Jan McDowell is running again, but she faces a crowded field. Kim Olson, a 2018 candidate for state agriculture commissioner, is running, along with Carrollton-Farmers Branch School Board Trustee Candace Valenzuela, psychologist John Biggan, ex-Carrollton-Farmers Branch Trustee Richard Fleming and attorney Crystal Fletcher.

Property manager David Fegan was running for the GOP nomination prior to the Marchant announcement. But other Republicans are almost certain to jump into the race, and former Irving Mayor Beth Van Duyne told The Texas Tribune on Monday she was running for the seat, with an official announcement coming soon. Van Duyne announced early Monday morning that she had stepped down Friday from her regional position with the U.S. Department of Housing and Urban Development.

At least one particularly interesting name is floating in Texas Republican circles: Matthew Marchant, the congressman's son and the former mayor of Carrollton.

The primary could also draw interest from current and former state lawmakers in the area. While ex-state Sen. Konni Burton, R-Colleyville, said Monday morning she was not interested in Congress, outgoing state Rep. Jonathan Stickland, R-Bedford posted a tweet Sunday night stirring speculation about his plans. And former state Rep. Matt Rinaldi, R-Irving, told the Tribune on Monday morning he was being encouraged to look at the race but had not made a decision yet.

The chairman of the House GOP campaign arm, U.S. Rep. Tom Emmer, R-Minn., issued a statement indicating he was bullish on his party's chances to retain the Texas 24th District.

"I’d like to thank Kenny Marchant for his decades of service to the people of Texas and our country, and wish him well in his retirement," he said.

“The socialist Democrats’ top candidate in this race is a war profiteer who was forced out of the military for disgracing herself in Iraq, and we will do everything in our power to keep her from getting anywhere near Congress," he added. “Simply put, this is a Republican seat and will remain a Republican seat in 2020.”

Emmer was referring to Olson, whose trailblazing career as an Air Force colonel ended after she was accused in the mid-2000s of steering government contracts to a private security firm that military investigators said she helped operate while she was stationed in Iraq.

Olson denied the charges and eventually pled guilty to two lesser offenses, including creating the appearance of a conflict of interest. She was allowed to retire with an honorable discharge and no reduction in rank, but she received a formal reprimand and a $3,500 fine.

Democrats, meanwhile, touted Marchant's retirement as another sign that Texas is a key congressional battleground in 2020.

“Congressman Marchant’s retirement comes just four months after the DCCC responded to the energy on the ground in Texas and opened an office there, placed six senior staffers on the ground, and deployed organizers in key communities across the state to lay the groundwork for victory next year," said Cheri Bustos, chairwoman of the Democratic Congressional Campaign Committee. "Clearly that investment is already paying off and Democrats are well positioned to compete and flip more seats in Texas.”

Before entering national office in 2005, the elder Marchant led a successful small business and homebuilding career. He launched a career in local politics in 1980, serving as a Carrollton City Council member and Carrollton mayor before going on to 18 years in the Texas House.

In Washington, Marchant is known for quiet work. In his decade and a half on Capitol Hill, Marchant has climbed the ladder of influence on the Ways and Means Committee, where he was nearing subcommittee chairmanship, in addition to serving on the Ethics Committee.

The senior representative joins an exodus of Texas Republicans, including U.S. Rep. Pete Olson, U.S. Rep. Mike Conaway, and U.S. Rep. Will Hurd. In several cases, members have stepped down ahead of facing toss-up races for seats they could once hold without much effort.

“Again, I want to thank the constituents of the 24th District of Texas for letting me serve and I look forward to being back in Texas full time," Marchant said on Monday.