When Jon Stewart retires from The Daily Show after more than 16 years as its anchor, his replacement should do the unthinkable: stop targeting the Fox News Channel. Forget CNN and MSNBC too.

The cable news networks may be the show's most reliable foil. They certainly broadcast ample footage of familiar characters making fools of themselves in high-definition. But Stewart has long since explored every possible angle of their absurdity. He's hugely talented and beloved, so most of his fans have enjoyed watching him do the comedy TV equivalent of greatest-hits concerts in recent years.

But watching someone else mock Fox for the next decade would be like watching another team vanquish the Washington Generals after the Harlem Globetrotters quit. That's an entertainment case for a new focus.

There's an intellectual case too. Back in 1999, when Stewart took over the Comedy Central program, cable news was still a rising phenomenon. Fox News was just three years old. Satire had not yet begun to probe its many absurdities, and doing so was important. But the danger in focusing on cable news foibles as much as any other subject for 16 years is the way in which it elevates the target. Daily Show viewers could be forgiven for thinking that the cable news networks are the most significant source of dysfunction in American democracy. Some perspective: There are 321 million Americans.