Ten minutes after Mitt Romney finished his speech at the Republican National Convention last week Judah Friedlander walked onstage at the Comedy Cellar in Manhattan and got to work solving the world’s problems.

Wearing baggy jeans and a baseball cap with a glittery American flag on the side, Mr. Friedlander announced matter-of-factly that he would solve any political challenge yelled out by the audience. Homelessness? Simple: Put everyone living on the street in tollbooths, a solution that he says makes sense because the homeless have experience asking for change. Drug crisis? Mr. Friedlander said he supports legalization, but he would start with heroin, because that would make legalizing marijuana easier.

Mr. Friedlander, whose chunky glasses and shaggy hair bring to mind the nerdiest pimp from the 1970s, is best known for playing the comedy writer Frank Rossitano on the NBC sitcom “30 Rock,” which begins its final season next month. But in his terrifically entertaining stand-up, which he has performed since 1989, he adopts a more flamboyant, overtly invented character whose brashness makes Donald Trump sound like Michael Cera.