Grant's 1995 appearance on NBC's "Tonight" show after aprostitution arrest, where Leno famously asked "what were youthinking?," was seen in retrospect as a turning point in thelate-night race. It drew a huge audience and propelled Leno to thetop of the ratings, a spot he would not relinquish.
Letterman did not court last week's battle with Palin, whocalled him "perverted" for making a joke about her daughtergetting "knocked up" by New York Yankee Alex Rodriguez, and hesaid in retrospect the remark was in poor taste.
Palin rebuffed his invitations to appear on the show, but thatmight not matter. The story had the effect of turning the attentionto Letterman at a critical time, during the second week of his newcompetition with Leno's replacement, Conan O'Brien.
"It will be interesting to see if that can be maintained orwhether it is one of those temporary things," said RobertThompson, director of the Center for the Study of PopularTelevision at Syracuse University.
The final numbers won't be out until later in the week, butthere's a strong chance that Letterman could average more viewersthan the "Tonight" show in the second week of O'Brien's new 11:35p.m. job. That hasn't happened since 2005, and the timing issignificant: some of Leno's old fans may be more amenable tosearching for a new late-night habit during the transition period.
It's difficult to tell whether Letterman received a boost thisweek because of people interested in what he was going to say aboutPalin. Strong guests like Julia Roberts and Denzel Washington werea boost, too.
Letterman has referenced the NBC transition in a handful ofjokes over the past two weeks, many of them poking fun of himselfas much as his rival.
"Conan O'Brien, of course, is the new host of the 'Tonight'show,"' Letterman said a week ago. "Did they even look at myaudition tape?"
On a top 10 list of Signs it's Time for Kim Jong-Il to retire,was No. 2: "Republic already named his successor, Conan Jong-Il.Topping the list of Surprising Facts about Sonia Sotomayor was:"Demonstrated impeccable judgment by watching Conan."
Despite the competition, no doubt it's hard for Letterman toexhibit the same animosity toward O'Brien as he did toward Leno.O'Brien has openly acknowledged his debt to Letterman, and hissubversive anti-talk show style is more reminiscent of whatLetterman did in the 1980s than what Letterman is doing today.
Letterman maintains his biting sarcasm, but at age 62 he hasevolved into more of a traditional talk show host than his rivals.Thompson said he believes Letterman is more topical than ever, inpart a recognition of Jon Stewart's success at Comedy Central. TheLetterman of two decades ago attracted attention for droppingwatermelons from the roof of a building or wearing a Velcro suit;now he gets it for charged interviews with John McCain or JoaquinPhoenix.
When Letterman did a brief filmed skit last week tied toWashington's new movie, "The Taking of Pelham 1 2 3" it seemedlike a quaint throwback; O'Brien does such pre-filmed segments allthe time.
"David Letterman's biggest problem is he was brilliant in goingagainst the grain," he said. "David Letterman is now the grain.He's his own toughest act to follow. So that's why it is smart thathe has tried to change the game."
Letterman, who went through a life-changing heart surgery andbecame a father in the past decade, seems committed to the newcompetition. It was revealed this week that he had agreed to acontract extension that will keep him on the "Late Show" into2012, and there's no indication that he's looking towardretirement.
His longevity, however, may be his biggest handicap in gettingback to the top.
"By and large, late-night comedy is a young wise-guy'sbusiness," Thompson said.
The fans who thought he was fabulously hip in the 1980s now havetheir own teen-agers looking to make their own late-night TVhabits. Letterman has a love-him-or-hate him personality, and atransition by one of his competitors isn't likely to change theminds of viewers who made them up years ago. He jokes about allpoliticians but it's becoming clearer where his sympathies lie --something that Palin and her supporters sensed in their criticisms.NBC has touted O'Brien's show as the fun place to be in late-night,particularly for younger viewers, with the implication thatLetterman is a cranky old man.
It would be foolish to count him out.
Palin may have inadvertently given Letterman a platform at atime when it is most valuable; the next few weeks will show howhe's been able to use it.