As on-target and incendiary as Chris Rock’s stand-up routines can be, he has yet to hit a consistent stride of hilarity in any big-screen outing. With more than a handful of laugh-out-loud bits, Head of State is his best effort yet. But a constant barrage of jaw-droppingly lame jokes sends the film into a tailspin from which it can’t completely recover.

Moving into the realm of high-concept comedy, Rock co-writes, directs and stars as Mays Gilliam, a Washington, D.C. alderman who prides himself on helping the people in his neighborhood by bucking the political mainstream.

When Mays hears news of the Democrats’ 2004 presidential candidate dying in a plane crash, he wonders who the party’s new nomination will be. Little to his knowledge, they’ve selected him even if it’s not to win. 

A string-pulling senator (James Rebhorn) merely wants Mays to get enough visibility as a minority candidate so he can take the election in 2008. No pushover, Mays decides he wants to win and learns to play the game his own way, urbanizing his campaign and selecting his literally slaphappy brother Mitch (Bernie Mac) as his running mate.

Head of State is strongest whenever it lets Rock and the sorely under-used Mac essentially recreate their stand-up routines onstage. 

When Mays flips off the TelePrompTer to coin his campaign phrase “That ain’t right,” it’s the same kind of witty, take-no-prisoners assault Rock launches at the microphone. The same holds true in Mays’ climactic debate speech with his cartoonish Republican opponent, who himself is a good, albeit over-tapped, source for laughs.

And as Mitch makes the rounds for the political pundits, Mac’s confrontational style of comedy shines. Too bad it’s not as funny when he is punching everyone in sight, which epitomizes why Head of State never quite clicks: Running gags, preferably, should be funny.

If the scene when Rock and Mac are slugging each other were not so loud, you’d be able to hear the crickets chirping in the dead, laugh-free air. In at least six inexplicably torturous scenes, the shrill, unfunny Robin Givens shows up as Mays’ psychotic ex-girlfriend. 

Rapper Nate Dogg, who offers running musical commentary a la There’s Something About Mary, is a little-used bright spot. And it would be funnier if Rock taught a group of elderly, white Democrats how to do the Electric Slide instead of them just knowing it.

R-rated comedies rarely are good business decisions when it comes to box-office receipts. Perhaps the problem is Rock’s comedic distillation in pursuit of the almighty PG-13 dollar. That’s not saying the comedian must be dirty, it’s that he must be daring. There are several such moments in Head of State, but it’s still not the movie that Rock’s fans know he’s capable of making.