IN THIS MEDIUM-HEAVY town, coverage of your favorite U.S. senator in action may not prove to be a top draw. But if the nationwide popularity of those cable telecasts from the House is any indicator, a Senate show might play quite well across the land and its screens. This, coupled with a belief in the "public's right to view the legislative process on a firsthand basis," can explain why Majority Leader Howard H. Baker Jr. wants to put cameras in the chambers.

For many Americans, it turns out, the pictures from the House are the first good chance they've had to watch their federal government in action. "Action" may be an overstatement, since the camera coverage is restricted to a stare-at-the-well angle that doesn't always tell the whole story. Still, the script can get colorful, the actors are many and on a good day the plots can come in layers. Senate coverage is bound to be better on this point, since the cast of this "Club 100" likes to use the whole set, wandering from desk to aisle and back, and the cameras would follow them around.

According to a study by the Senate Rules Committee staff, tests performed in this chamber indicate that eight studio-sized cameras sited around the galleries could provide "a full head-and-shoulders closeup of each senator." That may do nothing for clarity of thought, but House viewers already know that in the event of fuzzy thinking, no adjustment to your set is necessary.