You can’t go home again. Thomas Wolfe wrote the book on that, but I learned it from “Leave It to Beaver.”

Let me explain. In one episode of the ancient sitcom, Beaver and his buddy try to relive a really fun day from their past. They revisit all the old places and do all the same things, but at the end of the afternoon, they are left with a hollow, empty feeling that can be assuaged only with milk and cookies and a hug from Barbara Billingsley. You just can’t return to the past and re-experience old magic.

I was reminded of the Beav’s nostalgic quest while watching “American Idol” (7 p.m., Fox) slog through the monthlong audition process that ended last week. Wasn’t that a bore? The whole process seemed to be a stale repeat of auditions past with the sole purpose of dredging up another exhibitionist like William Hung. And in the end it didn’t even succeed on that level.

The ordeal seemed to be the show’s perverse way of punishing its faithful audience. It’s as if they were saying, “You idiots will sit through anything, and we do mean anything.” The ratings have been very strong, so perhaps the “Idol” folks are right. But a day will come when even the most loyal viewers will begin to feel abused.

But as of tonight, it’s on to Hollywood, where the auditions really matter and the performers are presumably doing their best.

I strongly recommend that “Idol” shorten the hideous and tedious audition process to a week, tops. Otherwise, it may succeed in killing or at least hurting the strongest franchise on network television.

¢ Does the “Scooter” Libby trial confuse you? Join the club. Is it about the government using the media to punish an administration critic? Or is the real scandal the media’s cozy relationship with its sources? This subject and others get a thorough going-over on the four-part “Frontline” (8 p.m., PBS) piece, “News War.”

The first two parts (tonight and Feb. 20) look at the increasingly adversarial relationship between the government and the media. Part three (Feb. 27) examines corporate ownership of the media and the pressures to increase profits that are making it more difficult to gather news. After a monthlong hiatus, part four (March 27) will examine how foreign news services are affecting journalism and politics in the United States.

Tonight’s other highlights

¢ The 113th Westminster Dog Show (7 p.m., USA) continues.

¢ Lorelai uses a dog’s funeral to distract herself from marital woes on “Gilmore Girls” (7 p.m., CW).

¢ “Nova” (7 p.m., PBS) presents “The Last Great Ape,” an examination of how war and poaching have decimated a primate population in Africa.

¢ A rapper’s murder calls for new tactics on “Law & Order: Criminal Intent” (8 p.m., NBC).

¢ A patient arrives who can’t feel a thing on “House” (8 p.m., Fox).

¢ An attack on a mob lawyer leaves one traumatized witness on “Law & Order: Special Victims Unit” (9 p.m., NBC).

¢ The fat hits the fire for Denny on “Boston Legal” (9 p.m., ABC).