WASHINGTON — Secretary of War Pete Hegseth is ruling out taking a Senate appointment to avoid a grueling impeachment fight — as President Trump considers whether to make him his whipping boy for the brutal midterm election wipeout.

Hegseth, who advocated for and oversaw the conflict that caused steep Republican losses on Tuesday, faces a possible bipartisan impeachment vote this year and insiders believe Democratic gains in the Senate mean he would face a public trial next year that would scorch the administration.

The former Fox News personality’s cleanest offramp, ironically, is joining the Senate by gaining Tennessee Gov.-elect Martha Blackburn’s support to appoint him to her vacated seat.

But Hegseth ruled out that option even as Trump spoke with allies about whether to replace him.

“We will continue to drive [Trump’s] agenda at the Department of War — despite threats of sham witch hunts from Democrats — and Secretary Hegseth is 100% committed to leading the Department until the end of President Trump’s term in office,” said Pentagon spokesman Sean Parnell.

Many sources told The Post that Hegseth would be an obvious near-term option for removal after the drubbing, in part because Trump will have a much more difficult time gaining Senate confirmation for a replacement when power changes hands in January.

“Knives are definitely out for him among senior West Wing staff,” a source close to the White House said, cautioning, “I don’t know if it’s a foregone conclusion that he’s gone.”

A different Trump insider said the president is asking around for input on what to do about Hegseth.

The Pentagon chief is popular with the conservative base but indisputably bears significant responsibility for the war, which both Trump and Vice President JD Vance said was a top cause of the landslide loss because of a surge in energy prices and inflation.

A third person close to the White House said “somebody has to own this.”

“When the word ‘war’ is in your title then you might be the person in the crosshairs,” he quipped.

A fourth person close to Trump said that if he were in Hegseth’s shoes, he would be begging Blackburn for the Senate appointment.

Trump dismissed mounting speculation about Hegseth’s fate, telling reporters Wednesday that Hegseth was “doing a very good job” and that he doesn’t plan to fire him, but that “he’d be very popular” if he chose to seek appointment to the Senate.

Trump, notably, used similar language while praising his former Attorney General Pam Bondi and former Homeland Security Secretary Kristi Noem before firing them this year.

John Ullyot, who served in national defense roles in both Trump terms, said, “Hegseth has been a human wrecking ball swinging through one of our oldest and proudest institutions, and it will take years to undo the damage.”

“He’s well past his sell-by date, and it’s time to give him the heave-ho,” said Ullyot, author of the new book “The President Deserves Better.”

“Any self-respecting leader with his record, in the military or the corporate world, would leave on his own before being shown the door.”

There’s historical precedent. President George W. Bush announced the resignation of Defense Secretary Donald Rumsfeld on November 8, 2006 — the day after heavy Republican losses in the midterm elections fuled by public dissatisfaction with the Iraq War.

Republicans lost seven seats in the Senate — with two additional losses possible — and have hemorrhaged at least 29 seats in the House, decisively swinging control of Congress to the Democrats, who are expected to block Trump’s legislative agenda and nominations and launch investigations that could lead to the president’s third impeachment.

The focus on Hegseth followed pre-election speculation that former White House deputy chief of staff James Blair, who currently works at the pro-Trump super PAC MAGA Inc., would take the fall for a possible backfire of the nationwide redistricting war he quarterbacked.

An internal assessment from the National Republican Redistricting Trust shared with The Post, however, found the redistricting push prevented an even worse GOP bloodbath.

The new House district lines likely allowed Republicans to hold one more seat in both Louisiana and Tennessee than they otherwise would have and between one and four more in Texas, the memo said — offset by projections of one or two additional Democratic seats in California.