In the end, Newt Gingrich turned himself into the one thing he had been trying to avoid by leaving the GOP presidential primary race ahead of the Tampa convention: a punchline.

Republican Presidential Candidate Former Speaker of the House Newt Gingrich leaves the stage with his wife Callista Gingrich, and grandson, Robert Gingrich, after publicly announcing his withdrawal from the 2012 Republican Primary race for President in Arlington, Virginia, Wednesday May 2, 2012. (Melina Mara/THE WASHINGTON POST)

In a 23-minute speech in the ballroom of the Arlington Hilton hotel, the former House speaker on Wednesday afternoon brought his campaign to a close nearly a year after it began.

He took swipes at President Obama and delivered a tepid endorsement of GOP frontrunner Mitt Romney that could best be summed up as the following: the enemy of my enemy is my friend.

And in bowing out, Gingrich made several joking references to his campaign-trail plan for a permanent moon colony – a proposal that has come to symbolize Gingrich’s descent from one of the most powerful players on the national stage to an also-ran often ridiculed for his often-grandiose ideas.

“I want to just say I’m cheerfully going to take back up the issue of space,” Gingrich, who spoke in front of a black velvet curtain and at a podium bearing his campaign logo, said as he came to the end of a long list of issues he said he intends to continue addressing in appearances across the country.

“My wife has pointed out to me approximately 219 times, give or take three, that moon colony was probably not my most clever comment in this campaign,” he continued. “I thought, frankly, in my role as providing material for ‘Saturday Night Live,’ it was helpful.”

Gingrich, who appeared wistful, was flanked at his good-bye speech by his wife, Callista; his daughters Kathy and Jackie; Jackie’s husband, Jimmy; and Gingrich’s grandchildren, Maggie and Robert, whom he called his “two best debate coaches.”

About a dozen supporters sat in the front rows of the conference room; the rest of the room was filled with about 60 reporters and 25 videographers and still photographers.

Toward the end of his speech, Gingrich again referred to his idea of permanently colonizing the moon.

“I’m not totally certain I will get to the moon colony,” he said. “I am certain Maggie and Robert will have that opportunity to go and take it. I think it’s almost inevitable on just the sheer scale of technological change.”

Of the election at hand, Gingrich said that he and Callista pledge to campaign for “a Republican president, a Republican House, a Republican Senate, Republican governors, Republican state legislators.”

“As for the presidency, I’m asked sometimes, is Mitt Romney conservative?” he continued. “And my answer is simple. Compared to Barack Obama? You know, this is not a choice between Mitt Romney and Ronald Reagan. This is a choice between Mitt Romney and the most radical leftist president in American history.”

Gingrich spoke last week with Romney and informed the former Massachusetts governor of his plans to bow out of the race, although he, like former senator Rick Santorum, has not yet officially thrown his support behind the GOP frontrunner.

Gingrich did offer some praise for Romney on the issue of job-creation; he told the crowd that the former Massachusetts governor and head of Bain Capital “knows about 60,000 times more than does President Obama” when it comes to creating private-sector jobs.

Romney later released a statement: “Newt Gingrich has brought creativity and intellectual vitality to American political life. During the course of this campaign, Newt demonstrated both eloquence and fearlessness in advancing conservative ideas. Although he long ago created an enduring place for himself in American history, I am confident that he will continue to make important contributions to our party and to the life of the nation.”

Of Obama’s visit this week to Afghanistan to mark the anniversary of the death of Osama bin Laden, Gingrich said it was “nice” that the president made the trip, but that “the center of al-Qaeda today is Yemen.”

“I’m not sure the White House has gotten that briefing yet, but they will eventually,” he said. “The fact that we assume our opponents are as stupid as our bureaucracy is very dangerous, and I think you have to recognize we do not have a grand strategy in this zone.”

Gingrich also strongly urged Republicans to support their candidates up and down the ballot in November, arguing that “a Republican sweep this fall would revitalize America just as the Reagan sweep of 1980 revitalized America. We have done it before. We can do it again.”

He thanked a long list of supporters and onetime candidates including Texas Gov. Rick Perry, businessman Herman Cain, Georgia Gov. Nathan Deal, as well as two of the biggest bankrollers of his efforts to stay in the race -- Sheldon and Miriam Adelson -- “who single-handedly came pretty close to matching Romney’s super PAC.”

In the waning days of his campaign, Gingrich drew crowds of only several dozen supporters, and his exit speech appeared no different.

Among those leaving Wednesday’s event were a group of a half-dozen 20-somethings who had been standing along one of the walls as Gingrich spoke.

Were they supporters of Gingrich?

No; they were engineers who worked at a predictive technology firm on the eleventh floor.

“We heard that traffic might be bad because Newt was in the lobby,” said one of them as they took the elevator upstairs and back to work.

This story has been updated.