Bigger in budget, grander in scope and proud of its own pointlessness, “22 Jump Street” is a self-reflexive joke at the expense of overblown movie franchises. It’s the sequel to end all sequels. The only problem: It’s so irresistibly funny it’ll probably spawn a trilogy.

Once again, thirtysomething cops Schmidt (Jonah Hill) and Jenko (Channing Tatum) are tapped to go undercover as students to bust a drug ring, this time at a university. As Deputy Chief Hardy (Nick Offerman) reminds them, two years ago nobody cared “about the Jump Street reboot, but you got lucky. So now this department has invested a lot of money to make sure Jump Street keeps going.”

Jenko whines about trying something original, like “joining the Secret Service and protecting the White House.” This reference to the plot of Tatum’s 2013 flop “White House Down” earns him a blistering glare. Just keep doing the same thing as before, Hardy growls, even though the partners can be sure that “it’s always worse the second time.”

The script takes gleefully satirical stabs at Hollywood. It ridicules the idea of “doubling the budget as if that would double the profit,” while reveling in expensive car chases, enormous spring-break crowd scenes and extravagant sets. The Jump Street division’s irritable Capt. Dickson (Ice Cube) fumes at full boil about the waste he sees all around. He declares indignantly that their overblown new headquarters looks like something from an “Iron Man” movie. Still, he’s thinking of adding a shark tank.

Rather than running from the déjà vu premise, returning screenwriter Michael Bacall and co-writers Oren Uziel and Rodney Rothman embrace it. Amazingly, they even make it meaningful. The cornerstone of both movies is the yin-yang partnership between clever, insecure Schmidt and delightfully obtuse Jenko. Here, like any couple in a mature, committed relationship — or sequel co-stars — they’re stuck in a template, doing the same thing over and over again.

Their new assignment introduces troubling turbulence. Jenko, joining the football team, acquires a new trophy bro, a young, fit blond quarterback/frat king named Zook (Wyatt Russell, who inherited great comedy genes from his parents Kurt Russell and Goldie Hawn). Older, frumpy Schmidt feels hurt, which leads to a delirious session of couples counseling from the school psychologist.

Hill and Tatum play the bro-dependent humor straight-faced; the possibility that their longtime friendship could be lost really matters. Like the best comedy, it’s funny because it’s somehow true.

As the cop team starts to fall apart, you genuinely feel for them. Tatum has a pure, almost childlike delight in big, silly jokes and X-treme stunts that defy the laws of physics, while Hill shines at sly comic characterization. They complete each other.

“21 Jump Street” alums Rob Riggle and Dave Franco make the leap to the sequel, now prison cellmates locked in their own partners-for-life sentence. Promising newcomers include Amber Stevens as a student who introduces Schmidt to hookup culture, and Jillian Bell as her acerbic roommate, who hammers away at how wrinkly and liver-spotted the new freshman looks, prodding him to “tell us about the war — any of them.” Several cameo pop-ins are inspired, on a par with Johnny Depp’s appearance in the original movie.

The directors of the first film, Christopher Miller and Phil Lord, deliver the same rambunctious energy and atomic-clock timing here. Gags fly by so fast they’re almost subliminal, from a Benny Hill shout-out amid a car chase to an inspired end credits sequence that ridicules every possible Jump Street spinoff and toy tie-in. Stick around through the very end. The film saves its last laugh until the moment when the theater crew arrives to sweep up.