The latest in a long ticket of political movies released on video this election season, Primary Motive stars Judd Nelson as an eager young press secretary for a gubernatorial candidate; Justine Bateman is his sexy girlfriend who enlists with the opposition to dig up compromising information. When she hits pay dirt, he calls in the bloodthirsty press — only to discover that his spin control has spun wildly out of control. Weighed down by lots of heavy talk about ethics in politics, this slow-moving drama lumbers to an unsurprising conclusion. We feel as if we’ve seen it all before-perhaps on last night’s newscast. Piling on the melodrama, the made-for-cable Primary Motive is supposed to be a scathing indictment of dirty tricks and candidates’ win-no- matter-what-the-cost mentality. But with its shallow good and evil characters and holier-than-thou posturing, the movie is as naive as Nelson’s character.