Turner Classic Movies presents the two-part documentary “Brando” (7 p.m. today and Wednesday, TCM) over two nights. It’s impossible to approach the history of cinema and acting in the second half of the 20th century without discussing Marlon Brando. For many, he was more than a star or an actor or an icon: He presented a demarcation in history.

“He is the marker,” says director Martin Scorsese. “There’s ‘before Brando’ and ‘after Brando.”‘ Michael Winner, who directed Brando in “The Nightcomers” (1972), also appears in the documentary and declares, “Before Brando, actors acted. After Brando, they behaved.”

From Dennis Hopper to Jane Fonda to Karl Malden to John Travolta, “Brando” calls on a list of acting, directing and producing talent too long to enumerate here. We also hear from family members and friends who share anecdotes about his turbulent upbringing and chaotic private life.

Brando the public figure projected ambivalence about fame and seeming contempt for his place in cinema history. It’s difficult to believe that the same man who transfixed audiences in “A Streetcar Named Desire” (11:30 p.m., TCM) and “The Godfather” appeared in “Superman” and seemed to ridicule his Vito Corleone performance in “The Freshman.” And who can forget an aging Brando with an ice-filled pot on his head in the bizarre 1996 remake of “The Island of Dr. Moreau.”

“Brando” recalls Sacheen Littlefeather, the American Indian representative Brando sent in his place to receive his 1972 Oscar for “The Godfather.” “He did not enjoy a lot of publicity at all,” recalls Quincy Jones. “Unless it was for something like civil rights or something that meant something to him. I always admired that. It was very real.”

¢ After a hiatus of what seems like most of the 2006-2007 season, “Veronica Mars” (8 p.m., CW) returns for May sweeps. In tonight’s episode, our 21st century Nancy Drew looks into a case of racial bias against the owners of a Middle Eastern restaurant.

¢ “The Gilmore Girls” (7 p.m., CW) also enters the last few weeks before its season or series finale, with Lorelai once again in hot pursuit of Luke. How do we know? She’s in full karaoke mode!

¢ Two contestants face the boot this week on “American Idol” (7 p.m., Fox). Just who will be in his or her “comfort zone”?

Tonight’s other highlights

¢ A parachute mishap on “The Unit” (8 p.m., CBS).

¢ A scandal blasts off the space pad on “Law & Order: Criminal Intent” (8 p.m., NBC).

¢ “The Mormons” examines the church in the 20th century on “American Experience” (8 p.m., PBS, check local listings).

¢ An ailing boy may be his dying brother’s only hope on “House” (8 p.m., Fox).

¢ The results are read on “Dancing with the Stars” (8 p.m., ABC).

¢ A bartender’s last call on “CSI: NY” (9 p.m., CBS).

¢ Benson’s half-brother puts her in a bind on “Law & Order: Special Victims Unit” (9 p.m., NBC).

¢ Shirley’s client may be down a pint on “Boston Legal” (9 p.m., ABC).

¢ Vic’s quest for vengeance may have marred his judgment on “The Shield” (9 p.m., FX).