ST. PAUL  — Democratic Rep. Keith Ellison, the first Muslim elected to Congress and a top official with the Democratic National Committee, filed to run for Minnesota attorney general Tuesday in a last-minute move triggered by the incumbent’s decision to run for governor.

A sixth-term lawmaker widely regarded as among the most liberal members of Congress, Ellison had been eyeing statewide office in Minnesota for months. He considered running for the Senate seat vacated by former Sen. Al Franken before backing Gov. Mark Dayton’s appointee, Sen. Tina Smith. And he weighed a run for attorney general until Lori Swanson, the current officeholder, decided to run for a fourth term this winter.

But Swanson changed course Monday, launching a late bid for Minnesota governor. Ellison and others pounced, filing for the office on Tuesday.

“It was attorneys general who led the fight against the Muslim ban,” Ellison said after filing to run for the office, referring to President Donald Trump’s ban on travel to the U.S. by visitors from several Muslim-majority countries. “I want to be a part of that fight.”

Ellison’s first statewide campaign will likely be far more challenging than his congressional runs. He represents a solidly Democratic district in Minneapolis and some surrounding suburbs and has never faced a major challenger since first being elected to Congress in 2006.

Ellison co-chaired the House’s Congressional Progressive Caucus from 2011 to 2017 and recently assumed the charge of pushing to expand a Medicare-for-all, single-payer health care program. He has also served as deputy chairman of the Democratic National Committee since 2017, after losing the race for its top job to Tom Perez. Both Ellison and the DNC said he would keep his spot as deputy chairman.

By entering the race for attorney general, Ellison is taking on the state party’s endorsed candidate as well as longtime Democratic state lawmaker and former Minnesota Attorney General Mike Hatch. All filed for the office Tuesday.

His decision not to run for a seventh term in Congress opens up a solidly Democratic seat. And Minnesota Democrats started lining up for a chance to take the seat before Ellison made his exit official.

State Sen. Patricia Torres Ray, a prominent voice on Latina issues, filed for Ellison’s seat less than an hour after he filed for attorney general. Former state House Speaker Margaret Anderson Kelliher also jumped in.

Another possibility was state Rep. Ilhan Omar, a Minneapolis Democrat and the nation’s first Somali-American state lawmaker. Neither Omar nor her office immediately responded to requests for comment.

Ellison said he wouldn’t endorse a successor.