NEW YORK - Television viewers welcomed late-night hosts with open arms for their first night back at work in two months because of a writers strike. Jay Leno's "Tonight" show on NBC was seen by 7.2 million viewers, or 43 percent more than what he had been averaging this season before the strike took him off the air Nov. 5, according to national ratings supplied by Nielsen Media Research. David Letterman's "Late Show" on CBS had 5.5 million viewers, 45 percent more than his pre-strike average, Nielsen said. Leno's writers are still on strike, while Letterman's production company (Worldwide Pants) struck a deal last week to bring his writers back to work. Later that evening, viewers were more interested in seeing how Conan O'Brien could cope without writers on NBC than how Craig Ferguson could do with them on CBS. Ferguson's show is owned by Worldwide Pants and governed by the same agreement as Letterman. O'Brien's "Late Night" had 2.8 million viewers, up 37 percent from his pre-strike average, Nielsen said. Ferguson's "Late Late Show" was seen by 2.2 million people, up 28 percent. Upon their returns Wednesday, a fully bearded Letterman walked onstage amid dancing girls holding picket signs supporting the striking writers. ABC's Jimmy Kimmel, working without writers, called pickets "ridiculous." The entertainment results Wednesday night were uneven. Leno delivered a monologue that included jokes he said he had crafted beforehand. Whether that violated rules of the striking Writers Guild of America — to which Leno belongs — was not immediately clear. "We are not using outside guys," Leno said in the monologue. "We are following the guild thing ... we can write for ourselves." The union said Wednesday it was withholding comment until it spoke to Leno about his show, which, like the other returning programs, was laden with references to the strike. The walkout, Leno joked, "has already cost the town over half a billion dollars. Five hundred million dollars! Or as Paul McCartney calls that, `A divorce.'" Guests on the shows included two presidential candidates — with Democrat Hillary Clinton making a cameo appearance on Letterman's union-sanctioned "Late Show" while Republican Mike Huckabee ventured across picket lines to play bass guitar and trade jokes with Leno on "Tonight." Letterman had the biggest celebrity guest, Robin Williams, who teased Letterman unmercifully about his beard, alternately comparing him to Gen. Robert E. Lee, a rabbi and an Iraqi mullah. Meanwhile, over on NBC, Leno segued from Huckabee to chef Emeril Lagasse and then rapper Chingy. O'Brien welcomed Bob Saget to pitch a new NBC show. Race car driver and "Dancing With the Stars" champ Helio Castroneves went to Kimmel. Ferguson appeared with no guests but a full complement of writers. "I just want to send a message to the D-list celebrities of Hollywood," Ferguson said. "You're still welcome here." Creative stretch marks were immediately evident on the shows without writers. O'Brien, sporting facial growth to match his red hair, showed off Christmas cards, danced on his table as his band played the Clash's "The Magnificent Seven" and tried to see how long he could spin his wedding ring on his desk. Leno took questions from his audience. There was also plenty of free on-air promotion for the guild's cause. "The writers are correct, by the way. I'm a writer ... I'm on the side of the writers," Leno said. "I want to make this clear. I support their cause," O'Brien said. "These are very talented, very creative people who work extremely hard. I believe what they're asking for is fair." Letterman brought writers on to recite a top 10 list of their strike demands. They included: "Complimentary tote bag with next insulting contract offer" and "Hazard pay for breaking up fights on `The View.'" "You're watching the only show on the air that has jokes written by union writers," Letterman said. "I hear you at home thinking to yourself, `This crap is written?'" Not all the hosts were as charitable. During his opening, Kimmel criticized WGA members picketing Leno and O'Brien: "I don't want to depart too much from the party line, but I think it's ridiculous. Jay Leno, he paid his staff while they were out. Conan did the same thing. I don't know. I just think at a certain point you back off a little bit." Huckabee appeared on Leno despite his apparent confusion about the strike and a bid by pickets to keep him away, and Clinton taped a cameo introducing Letterman. "Dave has been off the air for eight long weeks because of the writers strike," she said. "Tonight, he's back. Oh, well, all good things come to an end." Huckabee said he supports the writers and did not think he would be crossing a picket line, because he believed the writers had made an agreement to allow late-night shows on the air. But that's not the case with Leno. "Huckabee is a scab," read one picket sign outside Leno's Burbank, Calif., studio. The writers guild urged Huckabee not to cross their picket line after he flew out to California. "Huckabee claims he didn't know," chief union negotiator John Bowman said. "I don't know what that means in terms of trusting him as a future president." For fans of the late-night hosts, the controversy was secondary to seeing their favorites again. Chuck Gunther of Grand Junction, Colo., stood on a sidewalk outside of Letterman's New York studio on a frigid night hoping to get into the audience. "When Dave is live," he said, "it's fresh and new every night — instead of watching reruns of `Seinfeld.'"