BISMARCK, N.D. (AP) — North Dakota lawmakers are expecting a legal challenge to a proposed congressional age limit, and estimate $1 million to defend the measure up to the U.S. Supreme Court, in what some observers see as a likely test case.

A top legislative panel on Wednesday unanimously approved a $1 million cost estimate for the state to defend the age limit proposed in a constitutional initiative approved for the June 11 ballot. Some legal scholars and political observers have said a state age limit for members of Congress would be unconstitutional. They cite a 1995 U.S. Supreme Court ruling on term limits that states cannot set congressional qualifications beyond those in the U.S. Constitution.

“I think I see clear intent, whether it’s through media and their own spokesman, that the intent here is litigation, and they’re using the initiated measure process to push that litigation,” Republican Sen. Janne Myrdal said.

Republican Sen. Brad Bekkedahl said he “absolutely” foresees an age limit challenge being appealed to the U.S. Supreme Court.

The measure would prevent people from running for Congress if they could turn 81 during their House or Senate term. The $1 million fiscal impact will be listed on the ballot.

Measure chairman Jared Hendrix called the number “quite inflated,” and said age limits are popular.

“Over 40,000 people signed our petition to place this measure on the ballot. It should be expected that the state defends something that the people clearly want. It’s literally the job of our attorney general to defend our constitution and laws. If someone doesn’t want to do that job of defending, they should not be in those positions,” Hendrix said in an email.

It’s unclear who would challenge the age limit, if passed. Someone could challenge the age limit as unconstitutional on its face, or an affected candidate could sue, according to Deputy Attorney General Claire Ness.

The measure would require North Dakota’s attorney general to “zealously defend” the age limit, and would give any voter legal standing to enforce the age limit. Ness said it’s unclear what role, if any, the attorney general’s office would have as to the latter scenario.

The state would likely have to hire a special assistant attorney general, costs of which can vary, depending on the legal issues raised by the other side, the attorney’s hourly rate and whether the case goes to appeal, Ness said. Costs could easily be in the hundreds of thousands of dollars, she told lawmakers.

“I don’t think that $1 million is unreasonable as a high number. It could go beyond that,” Ness said.

The measure wouldn’t stop any incumbents from running again. The oldest member of North Dakota’s three-person congressional delegation is Republican Sen. John Hoeven, at 67. North Dakota has had octogenarian senators in the past, including Democrat Quentin Burdick, who died in office in 1992 at age 84.

While the initiative applies only to congressional seats, this election year will also feature President Joe Biden, 81, and former President Donald Trump, 77, competing in an election rematch that has drawn scrutiny of their ages and fitness.

The measure reads: “No person may be elected or appointed to serve a term or a portion of a term in the U.S. Senate or the U.S. House of Representatives if that person could attain 81 years of age by December 31st of the year immediately preceding the end of the term.”

The measure’s push emerged last summer amid age- and health-related scrutiny of members of Congress. Democratic Sen. Dianne Feinstein died last year at age 90 after health struggles. Republican Senate Minority Leader Mitch McConnell, 82, froze twice in front of reporters last year.