Jason Spencer, a Republican state representative in Georgia, found himself on the wrong end of a Sacha Baron Cohen prank that aired Sunday night on Showtime. It was the second episode of “Who Is America?” — Mr. Cohen’s latest foray into duping unsuspecting participants into saying embarrassing things.

But Mr. Spencer’s segment was one of the most humiliating yet to air on the show.

Mr. Cohen was playing a character named Erran Morad, an Israeli antiterrorism expert who, in the first episode, fooled several current and former lawmakers and gun-rights advocates into expressing support for arming young children. In Sunday night’s episode, the Morad character persuaded Mr. Spencer to take part in what he believed was antiterrorism training.

[Sacha Baron Cohen is duping Republicans. Is he the James O’Keefe of the left?]

For Mr. Spencer, it went downhill from there. In a series of wince-inducing scenes, Mr. Cohen got him to yell a racial epithet and drop his pants on camera by telling him that those tactics would scare terrorists away.

At the end of the episode, Mr. Spencer used another slur in referring to people from the Middle East. By Monday morning, he came under intense criticism from leading Republicans in Georgia. He issued an apology but rejected calls for his resignation.