An interesting film with a dumb title, “Poliwood” (6:30 p.m., Showtime) looks at the intersection of politics and celebrity. Director Barry Levinson (“Wag the Dog”) follows actors, including Matthew Modine, Susan Sarandon, Anne Hathaway and others, as they attend last summer’s political convention and January’s inauguration, and he shows how celebrities can steep themselves in issues and associate their famous faces with causes. But at the end of the day, do they enhance people’s understanding of issues, or drag every subject down to the level of spectacle?

We learn that Richard Dreyfuss has become an informed student of politics and that he has taught courses at Oxford. But when he discusses politics, he is dismissed as “the guy from ‘Jaws'” by those who disagree with him. And often, those very critics are merely radio or TV talk-show hosts with no particular political experience or credible education.

The most interesting aspects of “Poliwood” involve Levinson’s mixed feelings about television itself. He shows clips from his own movie “Avalon” to demonstrate how the arrival of a TV set changed the very nature of family life. Very soon, large multigenerational dinners and gatherings gave way to single families gathered silently around the tube, often watching insipid shows about the virtues of family life.

A not terribly focused 90-minute film about a vast subject, “Poliwood” also explores how ratings-driven talk/news shows have helped polarize government and the electorate because screaming matches are more “entertaining” than an informed discussion between reasonable people.

MSNBC analyst and “West Wing” producer/writer Lawrence O’Donnell observes that only PBS’s Jim Lehrer has maintained the notion of news as a civil forum and a public service, and that everybody else (including himself) is chasing ratings.

Why are so many Americans so badly informed about the rest of the world? Apparently, they don’t care. Tucker Carlson, now of Fox News, observes that the minute-by-minute ratings analysis shows that the second a newscast turns to a story about any foreign country or subject (“and that includes Tijuana or Ottawa”) the audience goes “right to ‘Wheel of Fortune.'”

Levinson readily admits that these qualms are hardly new. He repeatedly cites an article from a 1959 “TV Guide” warning about the impact of television on politics. Its author was Sen. John F. Kennedy, who would go on to be known as the first TV president.

Tonight’s other highlights

• The Yankees and Phillies meet in game 5 of the World Series.

• Hiro arrives just in time on “Heroes” (7 p.m., NBC).

• The wrong kind of wedding crashers on “Trauma” (8 p.m., NBC).

• An original presentation of “American Experience” (8 p.m., PBS, check local listings), “Civilian Conservation Corps,” recalls the New Deal program that put hundreds of thousands of Depression-era teenagers and veterans to work improving national parks and repairing environmentally ravaged farmland.

• Cappie and Casey reach a decision on “Greek” (8 p.m., Family).

• A groom vanishes after a rowdy bachelor party on “CSI: Miami” (9 p.m., CBS).

• A rocker’s last gig on “Castle” (9 p.m., ABC).

• “The People v. Leo Frank” (9 p.m., PBS, check local listings) recalls the trial and lynching of a suspect, who was both an outsider and a Jew, accused of a young girl’s murder in 1913.