A documentary, a call to action and a requiem all at the same time, “Schmatta: Rags to Riches to Rags” (8 p.m., HBO) recalls the rise, decline and fall of New York City’s garment district and presents its subject as an example of the disappearance of the American manufacturing economy, and with it, the American middle class.

The film makes smart use of graphics to demonstrate the decline of the industry, showing how changes in trade laws, consumer attitudes and vast shifts in culture and politics resulted in a market where American-made clothes have all but disappeared.

“Schmatta” repeats a central point that the garment industry thrived by helping immigrants join the middle class and by selling clothes to the middle class. Now, the industry aims at the high-end celebrity market and at the highly discountable market for Walmart and other retailers. And as one former designer, now bankrupt, observes: low, low prices don’t mean anything when you don’t have a job.

“Schmatta” mourns not only the loss of a district and an industry, but also the loss of the feeling of solidarity among workers, consumers and manufacturers that made the American middle class possible. Who, or what, changed this attitude? “Schmatta” offers suspects, but no definitive answers. Was it John Kennedy’s fault for opening the door to foreign textiles? Or Ronald Reagan for breaking American unions? Is Walmart a villain for their rapacious race to the cheapest supplier? Or are we all to blame? You don’t have to be a clotheshorse to know that sometimes you have to look in the mirror and face the truth.

• “American Carny: True Tales from the Circus Side Show” (8 p.m., Documentary Channel) takes an intimate look at folks who make their living working as circus freaks, fire eaters, human blockheads, magicians, contortionists and professional lunatics. Penn Jillette narrates.

• “Latin Music USA” (PBS, check local listings) concludes with “The Chicano Wave” (8 p.m.) set in the American West and Southwest during the latter half of the 20th century and “Divas and Superstars” (9 p.m.) a survey of crossover artists and Latin pop superstars from Gloria Estefan to Shakira.

• “Monty Python: Almost the Truth” (8 p.m., IFC) continues with a glance at the show’s first season and its growing popularity amongst college-age viewers and younger men and boys intrigued by its mix of arcane academic references, abject silliness and occasional nudity. Comedians from Dan Aykroyd to Eddie Izzard and Russell Brand discuss the show’s appeal as well as their favorite sketches.

Tonight’s other highlights

• “Bud Greenspan Presents: 2008 Beijing Summer Olympics” (6 p.m., Showtime) casts a wide lens on the competition and spectacle of last summer’s games.

• A history of heart failure dogs a reckless cop on “House” (7 p.m., Fox).

• Hiro mentors Emma on “Heroes” (7 p.m., NBC).

• A Chinese restaurant explodes on “Trauma” (7 p.m., NBC).

• A suspect takes drastic steps on “Lie to Me” (8 p.m., Fox).

• “Extreme Paranormal” (9 p.m., A&E) visits a New Mexico penitentiary.

Cult choice

In 1962, the clip anthology “Harold Lloyd’s World of Comedy” (12:15 p.m., TCM) introduced a new generation to the silent comedian’s most audacious stunts and funniest scenes.