Like moths to television lights, an almost giddy contingent of Congress members stopped by a reception last night for public television's weekly show on congressional action, "The Lawmakers."

Some came because the three hosts -- Paul Duke, Linda Wertheimer and Cokie Roberts -- are familiar fact-diggers on the Hill; others because they have a more familial relationship, Rep. Lindy Boggs being Roberts' mother and Speaker of the House Tip O'Neill being her former babysitter; and the others because they feel television seems to certify to the folks back home that their elected officials are working.

"All you have to do is express yourself intelligently, show a sense of humor and be well-behaved," said James Scheurer (D-N.Y.) of his television appearances. "Five minutes later they wouldn't know what you were talking about but they know you were there."

Clearly, the hosts observed as they looked around a Rayburn House Office Building room -- packed with politicians like Robert Stafford, Millicent Fenwick, Sonny Montgomery, William Lehman, William Green, Louis Stokes and John Seiberling, a flock of press aides, a dozen corporate representatives -- congressmen are not camera shy. "They have been expressing their availability," said Wertheimer. "When Congressman Jones, Jim of Oklahoma, the chairman of the House budget committee, was leaving, he said, 'I'll see you Thursday.' He's one of the guests."

"The Lawmakers," which originates at WETA (Channel 26) and is shown on most of the PBS stations nationally, had a successful test run last spring with Duke, a 23-year veteran of Capitol Hill reporting. Its second season, again on WETA, with the addition of Wertheimer and Roberts, award-winning correspondents for National Public Radio, marks the first major national collaboration between public radio and public television. "Every public TV station that counts has taken it," said Ward Chamberlin, the president of WETA.

"Two things make it click," said Duke. "It shows Capitol Hill as action-centered and it provides a continuity of issues. We make it focused." This Thursday, the show illustrates the ups and downs of television power: It gets bumped until the end of President Ronald Reagan's economic address, but then it gets a chance for the first rebuttal.