“The Education of Gore Vidal” on “American Masters” (9 p.m., PBS, check local listings) explores Vidal’s many contradictions. He’s both a popular writer and a serious scholar. He’s turned obscure subjects like the fourth-century Roman emperor Julian into best-selling books. He’s lived with the same man for decades and wrote “The City and the Pillar, the first popular novel with matter-of-fact homosexual characters, but he doesn’t consider himself a “gay writer.” He’s made American history the main subject of his shelf of novels, but he’s lived much of his adult life in Italy. He’s a distant cousin of Al Gore and shared a stepfather with Jacqueline Kennedy Onassis, but spent decades blasting Democrats.

He’s currently embraced by the left (he’s seen here being feted by the staff of The Nation magazine), but he began his political life as a fervent isolationist and foe of FDR. Like archconservative Pat Buchanan, Vidal longs for the day when America was a republic and not an empire.

Never afraid to probe and provoke, Vidal outraged almost everybody by writing an extended essay exploring the mind and motivations of Oklahoma City bomber Timothy McVeigh. And with all of this controversial baggage, Vidal still managed to be funny enough to be a frequent guest on “The Tonight Show” with Johnny Carson. They don’t make novelists, or Americans, like Gore Vidal anymore.

• “Watergate Plus 30: Shadow of History” (7 p.m., PBS, check local listings) glances back at the 1972 “third-rate burglary” that developed into “a cancer on the presidency” and eventually drove President Richard Nixon to resign. Interviewees include former White House counsel John Dean; Jeb Stuart Magruder, deputy chief of the Committee to Re-elect the President in 1972; Watergate Senate Committee counsel Sam Dash; former senators Lowell Weicker and Howard Baker; and reporters Carl Bernstein and Bob Woodward, who broke the story for The Washington Post.
• An extended Italian-American brood from Long Island takes over a fancy mansion as the absurd “reality” show “The Family” (8 p.m., ABC) returns. “The Family” was bumped from ABC’s schedule early this spring to make way for war coverage. ABC will condense three previously aired segments in tonight’s two-hour re-introduction. For the uninitiated, family members don’t know that the servants are secretly monitoring their behavior and get to decide who goes and who stays.

Tonight’s other highlights

• Scheduled on “60 Minutes II” (7 p.m., CBS): an interview with George Clooney; the mob’s enduring appeal; teens and domestic violence.
• Future grooms and brides-to-be submit to humiliating contests for a chance to win a fancy catered wedding on the new “reality” show “Race to the Altar” (7 p.m., NBC).
• Bartlet’s staff scrambles to round up key votes for a crucial bill on “The West Wing” (8 p.m., NBC).
• Michelle Branch, Simple Plan, Interpol and Chingy perform on “Pepsi Smash” (8 p.m., WB).
• Tom Berenger stars in the new series “Peacemakers” (8 p.m., USA) as the marshall of a 19th century town who uses forensic science to solve crimes.

Late night

Seann William Scott, Jonathan Ames and Fountains of Wayne appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno hosts Roseanne Barr on “The Tonight Show” (10:35 p.m., NBC).