George W. Bush and Dick Cheney are long gone. Fox News Channel is Jon Stewart’s new enemy No. 1.

Last week that comedian did something that the hosts of “Fox & Friends,” the morning show on Fox News, did not do: he had his staff members call the White House and ask a question.

It may have been in pursuit of farce, not fact, but it gave credence to the people who say “The Daily Show” is journalistic, not just satiric. “Fox & Friends” had repeatedly asked whether the crescent-shaped logo of the nuclear security summit was an “Islamic image,” one selected by President Obama in his outreach to the Muslim world. The White House told “The Daily Show” that the logo was actually based on the Rutherford-Bohr model of the atom.

“This is how relentless Fox is” in savaging President Obama, Mr. Stewart said.

On the subject of Fox, Mr. Stewart is pretty relentless too. As demonstrated by that crescent segment and dozens of others since Mr. Obama took office, he may well be television’s pre-eminent fact-checker of Fox News, the nation’s highest-rated cable news channel.

It has been noticed by, among other people, the Fox host Bill O’Reilly, who called Mr. Stewart a “devoted critic” of Fox News and said “his influence is growing.”