With “more discipline and more courage to be more outside the mainstream,” Newt Gingrich told USA Today on the eve of ending his presidential bid, “it might have worked better.”

Actually, Mr. Moon Colony was plenty outside the mainstream. But discipline? Yes, that might have helped.

Speaking Wednesday afternoon at an Arlington hotel, the former House speaker formally departed the GOP primary race in much the manner in which he ran his campaign: discursive, chaotic and utterly devoid of self-control.

For 23 desultory minutes in an overheating conference room, Gingrich took the 150 campaign workers and reporters present on a stream-of-consciousness tour of the Newtonian Mind. He spoke, in no particular order, of Capt. John Smith in 1607, mining asteroids, his novels about George Washington, Kaiser Wilhelm II, Ellis the Elephant, the Strait of Hormuz, Alzheimer’s disease, Chinese bondholders, Todd Palin, electromagnetic pulses, radical Islamists, C-SPAN, his high school years, Nixon, Carter, Reagan (both Ronald and Michael), the civil service, the Civil War, autism, holograms, the Soviet Union, nanoscale science, the Federalist Papers and Herman Cain.

He had little to say about the one thing people in the room cared about most — whether he would endorse Mitt Romney, the man Gingrich had dubbed a liar and a fake. Gingrich was tepid. “You know, this is not a choice between Mitt Romney and Ronald Reagan,” he said. “This is a choice between Mitt Romney and the most radical, leftist president in American history.”

Gingrich, who enjoys dinosaur fossils and zoos, chose instead to tell his captive audience about his pet projects. “I’m cheerfully going to take back up the issue of space,” he proclaimed. With his wife, Callista, in her usual place at his side, her mauve jacket perfectly matching her nail polish, he acknowledged that she was correct in telling him that his proposal for a moon colony “was probably not my most clever comment in this campaign. I thought, frankly, in my role of providing material for ‘Saturday Night Live,’ it was helpful.”

About this aspect of the Gingrich campaign there can be no dispute. He gave us child janitors, the Tiffany charge account, algae, a Greek cruise, the mass defection of his campaign staff and the “food-stamp president.” He told us he worked as a “historian” for Fannie Mae, boasted about his speaking fees, and mercilessly condemned Romney as a man who “can’t be honest,” who “looted a company” and who “doesn’t seem capable of inspiring positive turnout.”

After his win in South Carolina, a Gingrich nomination briefly seemed plausible. But that possibility was quickly extinguished to everybody but Gingrich. As recently as two weeks ago, Gingrich was vowing to remain a candidate until the Republican National Convention. The New York Times’ Mark Leibovich caught up with him last week and discovered that he was the only reporter in Gingrich’s entourage. Soon after, even Gingrich’s Secret Service detail abandoned him.

Gingrich exited with typical disorder. First he was preempted by an aide, who announced last week that the candidate would quit. This week, Gingrich preempted himself, making a video on Tuesday to give supporters “insider advance notice.” That left little mystery on Wednesday afternoon, only the contradiction of having Gingrich, who campaigned against Washington and the national media, making his formal announcement inside the Beltway to the national media.

It was, he said, “a truly wild ride . . . all just sort of amazing and astonishing.” Gingrich had the good manners to thank Sheldon Adelson, the billionaire who kept his candidacy afloat. He regaled the cameras with a long recitation of his well-known biography and a detailed list of his future plans (“I will focus again on national security in three zones” and “modernize unemployment compensation to attach to it a training component”).

By the time he reached his defense of the moon-colony proposal, most of the reporters in the audience had stopped writing. A sound technician covered a yawn. One man had his chin on his chest, asleep. The former candidate’s granddaughter, standing onstage, exhaled deeply and put an arm around her mother.

“This is not a trivial area,” Gingrich insisted. Perhaps not. But his rambling farewell was a reminder of why his candidacy, like his speakership, was destined to fail: Gingrich occasionally has brilliant ideas and strategies, but they are difficult to find amid the clutter of his mind and oratory, and that makes him seem unpredictable and unstable.

“I’m not totally certain I will get to the moon colony,” Gingrich acknowledged. But one thing is certain: He will always be way out there.