Soledad O’Brien hosts the four-hour documentary series “Black in America” (8 p.m. and 11 p.m., CNN, tonight and Thursday), an effort occasionally undone by its vast scope.

O’Brien does a good job of keeping the focus on the personal and anecdotal, visiting people on their way to a large family reunion and then sitting down with a family historian who has found some interesting branches in the genealogical tree.

To explore the problem of heath care in the black community, she talks with an iconoclast with a Ph.D. who throws out an interesting, if hard to prove, theory about slavery and hypertension and then spends some time with a woman from Harlem who explains just how many bus rides, cab fares and hours it takes for her to shop for fresh produce. Another voice observes that in some city neighborhoods, it’s easier to buy a gun than a fresh tomato.

That’s an amazing and memorable statement. And a reminder that sometimes shorter documentaries that focus on something particular – like the search for that tomato – can shed more light on their subject than a four-hour general approach like that of “Black in America.”

¢ Sporting a cast any sitcom producer would envy, “Sordid Lives: The Series” (9 p.m., Logo) offers a silly, way-over-the-top look at a gay actor’s (Jason Dottley) dysfunctional family back home in Texas. Imagine “Will & Grace” meets “My Name Is Earl” and you’re only getting close.

The performances are deliberately campy and the tone seems better suited to the stage, where “Sordid Lives” got its start. But the main cast, including Bonnie Bedelia, Olivia Newton-John, Rue McClanahan, Beth Grant, Leslie Jordan and Caroline Rhea, appear to be having the time of their lives.

The stereotypes of trailer-park denizens, Texas bars, church ladies gone astray and Valium-guzzling women with big hair may be off-putting to some, but I can’t imagine they are the target audience for “Sordid Lives” anyway. Look for a cameo by Georgette Jones, the daughter of Tammy Wynette, playing the spirit of her mother.

¢ “Night Shift: Repo Men” (8 p.m., National Geographic) looks at two New Jersey repossession agents as they retrieve items from the gritty streets of Newark and the posh quarters of Upper Montclair. Emilio Estevez is nowhere in sight.

Tonight’s other highlights

¢ The lads clash with their new sponsor on “Click & Clack’s As the Wrench Turns” (7 p.m., PBS).

¢ A British journalist travels to California to find “Plastic Surgery Junkies” (7 p.m., BBC America).

¢ “Nova scienceNow” (8 p.m., PBS) looks at leeches and surgery; the search for life in the universe; and the stem-cell revolution.

¢ The competition sports a green theme on “Project Runway” (8 p.m., Bravo).

¢ Amityville seems a little less horrible on “CSI: NY” (9 p.m., CBS).

¢ It’s interesting that a strike-shortened “Law & Order” (9 p.m., NBC) season would produce a plot about murder on the picket line.

¢ “Criss Angel: Mindfreak” (9 p.m., A&E) enters its fourth season with a walk on the wet side.

¢ Scheduled on “Scare Tactics” (Sci Fi, TV-14): stay out of the coffin (9 p.m.), interstellar traffic (9:30 p.m.).

Cult choice

“Ozzie Nelson and His Orchestra” (3:45 a.m., TCM) celebrates big-band music. Two decades later, his son Ricky would help popularize rock-and-roll on “Ozzie and Harriet.”