Former President Bill Clinton's top political strategists, who had a front-row seat for the Republicans' 1994 electoral successes, said Wednesday that the GOP today is peaking too early and is unlikely to see a repeat performance this November. Pollster Stan Greenberg said a "change election," as political scientists call major shifts in electoral preferences, already happened when Republican Scott Brown's surprise victory for Sen. Edward M. Kennedy's Senate seat, and between then and November, Democrats will have gained back ground. "When we look back on this, we're going to say Massachusetts is when 1994 happened," Mr. Greenberg said.