In an op-ed for Fox News, Republican presidential candidate Nikki Haley called on California Sen. Dianne Feinstein to resign, saying that the longtime Golden State lawmaker is a “prime example” of the need for politicians to submit to mental competency tests. 

Haley, in the opinion piece released Monday, called Feinstein a “trailblazer who’s made an indelible mark in public service,” but went on to claim that “it’s been obvious for quite some time that she’s in significant mental and physical decline.”

“She’s missed months of votes and clearly can no longer do her job,” Haley continued. “I agree with several congressional Democrats who say Feinstein should resign immediately and let someone else who is able to do the job take over. At 89 years old, she is a prime example of why we need mental competency tests for politicians.”

Feinstein's office declined to comment on the op-ed to Spectrum News.

Haley’s comments echo those made by a growing number of House Democrats calling on Feinstein, who has been absent from the chamber since February as she recovers from a bout with shingles, to step down.

Michigan Rep. Rashida Tlaib on Friday joined fellow House Democratic Reps. Ro Khanna, D-Calif., and Dean Phillips, D-Minn., in urging Feinstein to resign. Tlaib’s comments came in response to Senate Republicans and Democratic Sen. Joe Manchin voting to pass a resolution that would roll back a Biden administration rule aimed at curtailing pollution caused by heavy-duty trucks.

“Because Sen. Feinstein was absent, Republicans are passing legislation through the Senate, undermining the right of our residents to breathe clean air,” Tlaib wrote on Twitter last week. “And with a far-right judiciary targeting our human rights, we are unable to confirm judges. Sen. Feinstein must step down.” 

While Haley’s call may align with those of House Democrats, it may clash with the desires of Senate Republicans, who last month blocked an effort by Senate Democrats to replace Feinstein on the Judiciary committee.

In remarks last month, Senate Minority Leader Mitch McConnell, R-Ky., called Feinstein a “titanic figure” and a “close, personal friend,” adding that his conference “will not take part in sidelining a temporary absent colleague off the committee just so Democrats can force through their very worst nominees.”

Since Haley launched her 2024 White House bid, the former South Carolina governor has made mental competency tests for politicians a central theme of her campaign.

“In the America I see, the permanent politician will finally retire,” she said in a speech in February formally launching her candidacy. “We’ll have term limits for Congress and mandatory mental competency tests for politicians over 75 years old.”

"America is not past its prime; it's just that our politicians are past theirs,” Haley later added.

Her comments were seen as a jab at President Joe Biden, who at 80 is the oldest sitting president in U.S. history, as well as her old boss, former President Donald Trump, who at 76 is running for the White House again next year. 

But shortly after Haley announced her campaign, Trump backed her proposal and took it one step further, calling for all presidential candidates to undergo a mental competency exam — and added that he’d like to see a mandated physical test as well.

“ANYBODY running for the Office of President of the United States should agree to take a full & complete Mental Competency Test simultaneously (or before!) with the announcement that he or she is running, & likewise, but to a somewhat lesser extent, agree to a test which would prove that you are physically capable of doing the job,” Trump wrote on Truth Social in February. “Being an outstanding President requires great mental acuity & physical stamina. If you don’t have these qualities or traits, it is likely you won’t succeed. MAGA!”

Sixteen U.S. senators and 36 House members are 75 or older, accounting for about one-tenth of Congress.

Haley also made headlines last week after Biden announced his 2024 reelection bid when she told Fox News that the president would be unlikely to make it to the end of a second term.

“I think that we can all be very clear and say with a matter of fact that if you vote for Joe Biden you really are counting on a President Harris, because the idea that he would make it until 86 years old is not something that I think is likely,” Haley told the outlet.

Her campaign appeared to double down on that sentiment, writing on Twitter last week: “A vote for Joe Biden is a vote to make Kamala Harris president.”

In Monday’s op-ed, Haley also took aim at Biden and Harris, and called for both the president and Feinstein to take the Montreal Cognitive Assessment — a “rapid screening instrument for mild cognitive dysfunction,” according to the Department of Veterans Affairs — and make the results public.

“This is not a qualification for office,” Haley wrote. “Failing a mental competency test would not result in removal. It is about transparency. Voters deserve to know whether those who are making major decisions about war and peace, taxation and budgets, schools and safety, can pass a very basic mental exam.”