Chris Matthews hosts the hour-long documentary “The Kennedy Brothers: A Hardball Documentary” (6 p.m., MSNBC), looking back at the ways that Kennedy brothers John, Robert and Ted changed both the practice and promise of American politics.

The recent deaths of Eunice Kennedy Shriver at age 88 and Sen. Ted Kennedy at 77 serve as reminders that time has caught up with Ambassador Joseph P. Kennedy’s brood. When the Kennedys arrived on the national scene, they were symbols of youth and, to use one of the 35th president’s favorite words, “vigor.”

When Robert Kennedy paid tribute to his murdered brother at the 1964 convention, he did a rather remarkable thing. He quoted Shakespeare (“Romeo and Juliet,” to be exact).

“When he shall die, take him and cut him out into the stars and he shall make the face of heaven so fine that all the world will be in love with night and pay no worship to the garish sun.”

Kennedy seemed to touch on something powerful and enduring. In one of the most emotionally charged speeches in 20th-century political history, RFK was warning his listeners, his party and his country that to dwell on the past and on the tragic and on what might have been was to lose sight of the future. Decades after this speech, Robert Kennedy’s poetic warning about the allure of morbid nostalgia rings more true than ever.

• Cable television’s obsession with tattoos continues apace. The six-part documentary series “Marked” (9 p.m., History) will explore the use of ink and marking throughout history and cultures, and visit with some of the extreme contemporary subcultures that use skin art as a means of personal expression and community identity. It will also discuss how rituals of pain, marking and initiation have changed, evolved and remained the same over the centuries.

Among the “tribes” that “Marked” will visit are motorcycle clubs, urban gangs, prison gangs and various manifestations of “street” culture.

Tonight’s other highlights

• Little League World Series (7 p.m., ESPN).

• Tampa Bay hosts Miami in NFL preseason action (7 p.m., Fox).

• Indiana students compete to put on the best show in the documentary “Guys ‘n Divas: Battle of the High School Musicals” (7:30 p.m., Showtime).

• A corporate retreat becomes a killing field on “The Mentalist” (9 p.m., CBS).

• Heidi Klum hosts “Project Runway” (9 p.m., Lifetime).

• Hank treats a woman with visions in the season finale of “Royal Pains” (9 p.m., USA).

Cult choice

TCM devotes 24 hours to one of Hollywood’s coolest stars, who brought an alluring realism to brutal and intense movies. Ida Lupino holds her own with Humphrey Bogart and George Raft in the 1940 drama “They Drive by Night” (7 p.m., TCM).