But once Johnson gets to Washington, the movie deteriorates. He finds that the nation’s capital is Scam City, with legislators gobbling up graft from special interests. Director Jonathan Lynn and scriptwriter (and former Mondale aide) Marty Kaplan settle for heavy-handed, sub-Capra convention and sentimentality: Johnson the chiseler becomes an instant populist when he meets a kid who’s gotten cancer, possibly from a big utility’s power lines. This movie can’t compete with the real Washington we’ve seen in the Hill-Thomas hearings and other spectaculars. Hollywooden pols like Rep. Dick Dodge (Lane Smith) are no match for theatrical senators like Strom Thurmond or Howell Heflin. And Murphy’s slick shtik can’t compensate for material that too often mistakes silly for funny.