Midseason is a time of diminished expectations on television (that’s why cable premieres many of its original series around this time). Even dubbing these shows “replacements” implies they’re something less than the new shows that debut in the fall.

That’s why two series premiering tonight are pleasant surprises, if hardly groundbreaking TV.

The slightly more promising of the two is “Queens Supreme,” at 10 p.m. on CBS. Although it’s replacing a much higher-caliber show, the gritty “Robbery Homicide Division,” the drama still has some interesting characters and situations to offer.

“Queens Supreme” focuses on a group of judges at the Queens County Courthouse, led by the eccentric and cynical Jack Moran (Oliver Platt, “Bulworth”). Other judges are played by Annabella Sciorra (“The Sopranos”), Robert Loggia (“Jagged Edge”) and L. Scott Caldwell (“Waiting to Exhale”).

The show’s strength is its creative cases. In the debut, Moran and his jury are held hostage by an agitated, smoking juror during a trial to determine if the death of an elderly man who joined a smoke-enders program was caused by the stress of withdrawal. In another case, a has-been actress wants to salvage her career by selling a porn video she made with another TV star before they became famous, against her co-star’s wishes.

Another character in the series is Queens itself, one of the most ethnically diverse communities in the United States. Filming in the New York City borough lends the show a flavor it couldn’t get anywhere else.

One thing hindering this law drama is that little has been revealed about characters other than the colorful Moran. It’s hard for viewers to get emotionally invested in one-dimensional characters, and “Queens Supreme” is not yet equal to the sum of its parts. Up against NBC’s “Law & Order: Special Victims Unit,” it needs to get up to speed, and quickly.

Also, at 8 tonight, NBC attempts to cash in on the continuing if flagging popularity of “The West Wing” with another Washington-based drama, “Mister Sterling.”

As created by Lawrence O’Donnell Jr., a “West Wing” writer-producer, “Mister Sterling” tells the story of an idealistic man (played by Josh Brolin), the son of a popular longtime California governor (James Whitmore), who leaves his position teaching at a prison school after being selected to fill the remainder of a term in the U.S. Senate.

The Beltway novice makes some early stumbles, dropping one major bombshell, but his intelligence and common sense serve him well. In addition to receiving unsolicited advice from his father, he’s aided by the remnants of his predecessor’s staff, including chief of staff Jackie Brock (Tony winner Audra McDonald) and legislative director Tommy Doyle (TV veteran William Russ). Among the familiar faces populating the Senate are Harris Yulin, Gerald McRaney and Graham Greene, who plays California’s senior senator, “Thunderhawk” Jackson.

“Mister Sterling” has too much “Mister Smith Goes to Washington” in it for its own good. O’Donnell brought that Washington-insider feel with him. Too bad he couldn’t have brought Aaron Sorkin’s machine-gun dialogue with him as well (although some may consider that a plus).

“Mister Sterling” is a conventional drama about a man finding his way, and it’s buoyed by its able cast. O’Donnell drops enough intriguing subplots into the first two episodes to give the series potential for future weeks. It’s got the most meat of any of the network offerings in its time slot, although Fox’s MTV-style cops series “Fastlane,” just moved away from opposite “The West Wing,” certainly provides more flash.