WASHINGTON – How old is too old?

Launching her 2024 campaign, Nikki Haley took a potshot at both the 80-year-old incumbent, Joe Biden, and her former boss, 76-year-old Donald Trump – insinuating they’re mentally impaired, and demanding they and the rest of their generation prove they don’t have dementia before holding office.

“America is not past our prime. It’s just that our politicians are past theirs,” the former South Carolina governor told supporters. “In the America I see, the permanent politician will finally retire. We’ll have term limits for Congress and mandatory mental competency tests for politicians over 75 years old.”

The rule envisioned by Trump’s United Nations ambassador would hit five Texans in Congress right away – notably House Appropriations Chair Kay Granger of Texas, who just turned 79 – plus two others who would turn 75 by inauguration day 2025.

In all, Haley insulted 36 House members and 16 senators in her demand for a new generation of leadership, including 89-year-old Chuck Grassley. Iowans reelected him just three months ago. So, nabbing his endorsement for the caucuses might have gotten trickier.

The oldest member of Congress, Sen. Dianne Feinstein, D-Calif., three months older than Grassley, announced this week that she won’t seek reelection next year.

Fourteen other octogenarians might still be around to face the Haley rule, including former speaker Nancy Pelosi, 82, and Senate Minority Leader Mitch McConnell, who turns 81 on Monday, catching up to Sen. Bernie Sanders.

Haley is a spry 51, though she displayed a bit of confusion as she poked at the elders standing between her and the Oval Office.

“Mental competency” test usually refers to a courtordered assessment of whether a defendant understands the charges and proceedings, and can help lawyers mount a defense.

What Haley likely meant was neurocognitive or “mental status” testing like Rep. Ronny Jackson, R-Texas, conducted on Trump.

A year ago Jackson, a zealous Trump backer and former White House physician, called Biden “brain dead” and rounded up three dozen other Republicans to sign a letter urging him to take the Montreal Cognitive Assessment.

That’s a common tool for detecting dementia related to Alzheimer’s, stroke and other ailments.

At Trump’s request, Jackson conducted it after Trump proclaimed himself a “very stable genius” to refute a book about his erratic first year. Some mental health professionals called for a cognitive work-up, citing lack of impulse control and other signs of decline.

On Jan. 16, 2018, Jackson announced the results.

“He has absolutely no cognitive or mental issues whatsoever,” Jackson told the White House press corps, also declaring that despite his 239 pounds, one shy of obesity at 6 feet 3 inches, Trump was in “excellent” health.

Biden had an annual exam Thursday at Walter Reed National Medical Center.

A 5-page summary released by the White House makes no mention of cognitive testing.

Dr. Kevin O’Connor described him as “a healthy, vigorous, 80-year-old male, who is fit to successfully execute the duties of the Presidency.” Biden uses contact lenses and custom orthotics, has normal blood pressure and doesn’t drink alcohol or smoke.

Doctors attribute his stiff gait to spinal arthritis, ruling out Parkinson’s or other neurological cause.

Who’d be tested

Haley didn’t say how these tests would be mandated.

It would probably take an act of Congress, where the average age is 58, down three years since the previous election – suggesting the generational shift is already underway.

Besides Granger, four other Texas incumbents would have to sharpen their No. 2 pencils.

Rep. John Carter of Round Rock, is 81. Fellow GOP Rep. Brian Babin of Woodville turns 75 next month.

On the Democratic side, Austin Rep. Lloyd Doggett of Austin is 76, a year older than Houston’s Al Green.

Four more Texans are in their 70s, and would face testing by the end of Haley’s first term.

Austin Rep. Roger Williams, chair of the Small Business Committee, is 73. Rep. Michael Burgess of Pilot Point, a fellow Republican, is 72. So are Democratic Reps. Sylvia Garcia and Sheila Jackson Lee of Houston.

Sen. Ted Cruz is 52. Sen. John Cornyn, 71, would be seeking a 5th term in 2026. He wouldn’t have to test before then.

Haley also didn’t clarify whether her plan would apply only to federal office.

At the state level, the rule would have limited immediate effect in Texas.

Gov. Greg Abbott is safe for another decade.

Texas House Speaker Dade Phelan is just 47. Attorney General Ken Paxton is 60. Lt. Gov. Dan Patrick is 72.

Trump announced his comeback bid in November, and has cast a long shadow over the GOP field, particularly for former cabinet members like Haley who face a choice: distance themselves and alienate his base, or try to explain why they’re better than the one who brung ‘em to the dance.

Biden is expected to announce his reelection bid in coming weeks.

At the White House, press secretary Karine Jean-Pierre declined to comment on Haley’s proposal.

But as evidence of Biden’s fitness to serve out a second term, she cited his “grueling schedule” and legislative achievements, and the fact he spent 90 minutes on his feet Feb. 7 delivering the State of the Union address, then another hour schmoozing on the House floor.

(It was actually about 75 minutes plus a half-hour.)

“He’s clearly capable in so many ways and on so many levels, and he’s going to continue to do that in years coming,” she said.