WASHINGTON (AP) -- The head of the Republican Party, launching a broad indictment of the Democratic Party six months before midterm elections, is expected to charge Friday that the opposition can't find an election-year slogan, let alone agree on a broad agenda.And of course he's absolutely right. Wanna know why the Republicans have had it all pretty much their own way since 1968 (at least)? One word: Democrats. They're not just part of the problem, they are the problem.In an address to the Southern Republican Leadership Conference in Tennessee scheduled for Friday afternoon, Ken Mehlman will single out party leaders and two potential 2008 presidential candidates - Sens. Hillary Rodham Clinton and John Kerry - for criticism on a range of issues, from national security to the economy to judicial nominees.