In a significant legal move, Arizona Attorney General Kris Mayes, a Democrat, initiated a lawsuit on Tuesday challenging the decision of Republican leaders to deny a newly elected Democratic legislator her seat.

The legal action seeks intervention from a federal judge in Washington, D.C., to officially recognize Adelita Grijalva as a member of the House. It also requests permission for someone other than Speaker Mike Johnson, a Republican from Louisiana, to administer the oath if he refuses to do so.

The lawsuit, filed by Mayes’s office, argues that the core issue is whether a duly elected representative can be prevented from assuming their “rightful office” simply because the Speaker opts to keep the House out of “regular session.”

“If such authority were granted to the Speaker, it would allow him to undermine the electorate’s decision about their congressional representative by effectively suspending their representation for a substantial part of the two-year term established by the Constitution,” the lawsuit asserts.

“Thankfully, the Constitution does not endow the Speaker—or anyone else—with such power,” it further contends.

A former county supervisor, Grijalva won a special election last month to fill the seat held by her late father, former Rep. Raúl Grijalva (D-Ariz.). The district spans most of Arizona’s southern border, part of Tucson. 

Johnson has repeatedly defended his move not to seat Grijalva, saying he’s just following a long-held House tradition of swearing in new members only during regular sessions.  

The speaker has canceled votes during the shutdown, and Johnson says he’ll call the House back to Washington and immediately seat Grijalva when Democrats help to reopen the government. 

“I will administer the oath to her, I hope on the first day we come back, of the legislative session,” Johnson told reporters Monday. “I’m willing and anxious to do that. In the meantime, instead of doing TikTok videos, she should be serving her constituents.” 

In recent days, House Democrats have also warned that swift legal action could follow if Grijalva is not seated. 

“This has gone on now for weeks,” Jeffries told reporters in the Capitol on Friday. “And so it’s my expectation that, if she is not sworn in today — during the pro forma session today — as the Arizona attorney general has made clear, expect swift and decisive legal action.”   

Grijalva said in a statement that Johnson’s “obstruction” is long past “petty partisan politics.” 

“It’s an unlawful breach of our Constitution and the democratic process,” she said. “The voters of Southern Arizona made their choice, yet for four weeks, he has refused to seat a duly elected Member of Congress – denying Southern Arizona its constitutional representation.”