WASHINGTON – Soon-to-be-ex-President Donald Trump left the White House early Wednesday and will spend his final minutes in office at his Mar-a-Lago estate in Florida – though he also suggested he will seek to remain in political life.

“We will back in some form,” Trump told supporters during a farewell ceremony at Joint Base Andrews that featured a 21-gun salute and a military band playing “Hail to the Chief.”

In a nine-minute speech on “an incredible four years,” Trump recounted highlights that included the creation of Space Force, veterans benefits, and the 2017 tax bill.

The outgoing president did not mention his two impeachments, nor the more than 400,000 Americans who have died of COVID-19; he did warn backers to “be careful” in the face of the “horrible virus.”

“What we’ve done has been amazing by any standard,” Trump said.

He did not mention incoming President Joe Biden, but did a crack a joke about him and his supporters: “I hope they don’t raise your taxes … But if they do, I told you so.”

Earlier, Trump told reporters it was the “honor of a lifetime,” as he and first lady Melania Trump boarded the Marine One helicopter that lifted off from the South Lawn at the White House at 8:17 a.m.

Trump plans to be at Mar-a-Lago, his Palm Beach club he dubbed the “Winter White House,” when the clock strikes noon, ending a contentious presidential term that closed with days of seclusion after a riot the U.S. Capitol and was capped with the final military send-off at Joint Base Andrews that drew a couple hundred supporters.

Trump is the first president in more than 150 years to skip the inauguration of his successor.

Trump’s departure came just hours after he released a list of nearly 150 pardon and commutations and day after a videotaped “farewell address” that suggested a preview of another Trump presidential run in 2024.

“As I prepare to hand power over to a new administration at noon on Wednesday, I want you to know that the movement we started is only just beginning,” Trump said in the taped address released Tuesday.

More:From the border to the federal bench to raging political divisions: How Donald Trump’s tenure has changed America

More:The Trump years: USA TODAY editorial cartoonist Mike Thompson looks back

Republican congressional leaders Mitch McConnell and Kevin McCarthy, both critical of Trump in the wake of the Capitol insurrection, were not at the sendoff. They planned to attend a church service with President-elect Joe Biden less than an hour after Trump was scheduled to depart Andrews for one last ride aboard Air Force One.

In invitations to supporters, the White House said guests could bring up to five people to the event, a sign they are trying to pack the crowd.

Even former aides received invitations, but have sent regrets.

That group includes Anthony Scaramucci, who served as White House Communications Director for 11 days in 2017 and is now an outspoken critic of Trump.

Scaramucci said he wouldn’t be attending the Andrews ceremony: “Uh, yeah, I have an appointment to get my fingernails pulled out, so I can’t make it.”

Given the rancor of recent weeks, it’s not known what Trump will do publicly after Wednesday’s exit. He has spoken about another presidential race in 2024, but it’s not known where that stands.

Trump and his aides once talked about holding a campaign rally on or before the day of Biden’s inauguration. That talk ceased after the riot at the U.S. Capitol that led to Trump’s second impeachment.

One thing on Trump’s immediate agenda: Preparing some kind of defense for a Senate impeachment trial on charges of inciting an insurrection.

The Air Force One ride to Mar-a-Lago will end a presidency like no other – and a transition like no other.

In addition to disputes over a COVID pandemic, a government shutdown, immigration, and racial unrest, Trump also was impeached twice. The first time for pressuring the government of Ukraine to investigate Biden and his son, the second time for inciting the Jan. 6 insurrection at the Capitol.

Never one to respect political norms, Trump spent the last two months protesting his election loss to Biden in an unprecedented manner. He filed lawsuits, pressured lawmakers and repeated baseless claims of widespread fraud in the election.

His false accusations of election fraud in a half-dozen states fueled extremist supporters who stormed the Capitol, demanding that lawmakers overturn the election.

Trump has spent much of the time since speaking privately with supporters and making the occasional video after being banned from social media websites.

The lame duck president hasn’t made a public appearance since a Jan. 12 trip to South Texas to deliver an immigration speech near the U.S.-Mexico border.

Along the way, Trump has ignored Biden in ways without parallel.

The incumbent president has not met with his successor. It is doubtful that Trump will write the traditional note of encouragement that outgoing presidents leave for successors (as President Barack Obama left for Trump).

More:Republican leader Mitch McConnell: Attack at the Capitol was ‘provoked by the president’

More:Planning for elections in 2022, Democrats set up ‘Trump Legacy Project’

In the past, outgoing presidents and first ladies have welcomed new first couples to the White House on the morning of the inauguration. Presidents and presidents-elect have ridden together to Capitol Hill for the ceremony. Afterward, new presidents and first ladies usually pose for pictures at the Capitol with their predecessors. The new president typically sees the new ex-president off to a helicopter for the ride to Andrews air base.

Trump’s absence means none of these traditions will happen Wednesday.

Immediate ex-presidents are given a courtesy plane ride back home.  Trump will still be president when he takes his last trip aboard Air Force One.

Trump is the first president to skip the inauguration of his successor since 1869, when impeached President Andrew Johnson avoided the swearing-in of President Ulysses S. Grant.

A father-and-son set of presidents – John Adams in 1801 and John Quincy Adams in 1829 – left Washington before the inaugurations of successors Thomas Jefferson and Andrew Jackson.

Some analysts said it’s just as well that Trump won’t be at Biden’s inaugural.

“Don’t need him rolling his eyes and making faces at the camera while Biden speaks,” tweeted historian Michael Beschloss. “When leaders come together to display national civility and unity, it has to be genuine and heartfelt.”