A dozen competitors hope they’re good enough to make the top eight as the semifinals begin in Los Angeles on “America’s Got Talent” (8 p.m., NBC).

Fox counters the real musical competition with a repeat of “Glee” (7 p.m.) that celebrates the music, message and phenomenon of Lady Gaga.

I’m a critic and not a soothsayer or a trend predictor, but one gets the distinct sense that the bloom is a tad off the “Glee” rose. The most obvious sign of “Glee” fatigue is the less-than-rapturous response to the recently released 3-D “Glee” movie. Many pundits thought the show’s cult fan base would turn out for the film, particularly those unable to see its live concert show. But some moviegoers were underwhelmed by the film’s 3-D effects. Others may have felt that 3-D was simply one extravagance too many piled upon a “Glee” experience that always takes excess to the extreme. Or maybe folks are simply balking at the 3-D movie gimmick, which can be viewed as just another excuse to raise ticket prices.

Whatever the reasons, the film did not take in as much at the box office as anticipated, and some critics have even used the word “bomb” to describe its opening.

Silly summer movies can sometimes be just that, a forgettable fling, quickly forgotten. But sometimes they can be the beginning of the end. I distinctly remember a time about a decade ago, when the Cartoon Network’s “Powerpuff Girls” franchise seemed to rule the earth. You couldn’t walk down the street — or the aisles of Walmart — without encountering merchandise based on Bubbles, Buttercup and Blossom. (The things you remember!)

But then the geniuses behind the franchise launched “Powerpuff Girls,” the movie. It was a bad movie and it bombed, and suddenly the “Girls” didn’t seem that ubiquitous anymore. Rather than take the cartoon to new, stratospheric heights, the movie did just the opposite. A fad balloon had been popped.

Am I predicting the same for “Glee”? I’d never do that. As I just said, I’m not in the prediction business.

• After competing for cable viewers all summer, TNT and USA (home to “Memphis Beat” and “Covert Affairs,” respectively) take a break with two hours of “Law & Order” repeats (8 p.m. and 9 p.m.) on TNT and “Law & Order: Special Victims Unit” repeats all day on USA.

Tonight’s other highlights

• A parking space to die for on “NCIS: Los Angeles” (8 p.m., CBS).

• Family portrait day on “Raising Hope” (8:30 p.m., Fox).

• A close call inspires a flashback on “NCIS” (9 p.m., CBS).

• A chaplain’s faith is shaken on “Combat Hospital” (9 p.m., ABC).

• Animated mini documentaries on “Short Cuts” on “POV” (9 p.m., PBS, check local listings).

Cult choice

A Bogart-like gumshoe (Harrison Ford) hunts rogue replicants in a bleak (not to mention damp) future Los Angeles in director Ridley Scott’s visionary 1982 sci-fi fantasy “Blade Runner” (8 p.m., Syfy).