For one thing, Little already uses a Dolly Parton joke somewhere else in his Golden Nugget show. But the real issue is this: If Little were to just drop in a contemporary name willy nilly into his anachronistic showcase, it would throw the whole act off kilter.

The impressionist, who turns 69 on Monday, has been increasingly dismissed for his time warp gallery of voices, which still are rooted in the celebrity universe that he orbited in the '70s.

But those who would advise Little to take a more contemporary approach should think twice. Do you really want a guy with doctored hair, looking more and more like Richard Nixon (one of his favorite subjects) with each passing year, to be imitating Will Smith?

Judging by two of his more current attempts -- Dr. Phil (McGraw) by way of Forrest Gump, or the we'll-take-his-word-for-it impression of Fred Thompson -- Little is just fine staying within his world; the one where Carson is still the late-night king, Archie Bunker ruled prime-time and Paul Lynde was king of the Squares.

Age actually gives the impressionist extra authority and a touch of poignancy for nostalgic takes on stars no longer with us, from George Burns and Jack Benny, to Jack Lemmon and Walter Matthau.

Even the Trickster gets an honest laugh in an otherwise apolitical rewind of modern presidents. Compared to administrations we've seen since 1974, "I really wasn't so bad," his Nixon says with some resonance.

Until the final 20 minutes, you could say this downtown residency is a worthy option for an older demographic that's no longer considered on the Strip. But when Little opens his mouth to sing in the homestretch, he pushes even their good graces.

Little never has been a great singing impressionist, but he seems to consider it a mandatory part of a casino gig. He says that he learns a voice by first studying tape of the subject, then playing back tape of himself doing the voice.

He should be forced to listen to a playback of this show, then search his soul to see if at least half of the voices in the final onslaught should be retired. Sure, he gets by -- as nearly all impressionists do -- with the predictable riffs on Tom Jones, Dean Martin, Sammy Davis Jr. and Willie Nelson. The fact that he remembers Anthony Newley, and does so fairly well, draws a generational line in the sand determining who should or should not buy a ticket to this show.

But Tony Bennett? Michael Crawford? Robert Goulet? Kenny Rogers? Neil Diamond? Glenn Campbell? Frank Sinatra? They all sound surprisingly like Rich Little.

He's on far more solid ground with his "Celebrity Quiz" parody of "Hollywood Squares," giving ample time for extended riffs on Burns, Carson and Jimmy Stewart that remind us he really can be a formidable mimic.

Of course, we've already been reminded in a preshow video montage that spans the years from Little's 1963 breakthrough, on a Judy Garland TV special, to his days of hobnobbing with President Reagan.

With an act that's in danger of being upstaged by it's opening video, Little should think about turning it into an autobiographical revue. The showcase could incorporate the clips, along with all the celebrity encounters from his days as the ultimate talk-show couch sitter.

At the very least, it would be an inscrutable way to keep living in the past.

Contact reporter Mike Weatherford at mweatherford@reviewjournal.com or (702) 383-0288.