Here's the scene: A conservative president, say President Bush, is getting ready to be replaced by a liberal, say Sen. Hillary Rodham Clinton, after a crisis like something worse than 9/11. The nation's national security team is worried that the nation is going to pot. So much so that the heads of a 400-person "supermilitia" created to overthrow governments on behalf of Washington move in to dump Bush, stop Clinton's ascension, and rebuild the nation. Crazy? No, it's just the premise of America's Last Days, a new political thriller out next month and already being looked at by Hollywood. Author Douglas MacKinnon, a former Pentagon, Reagan, and Bush aide, says it rings true. His scenarios were so real"many of the people are at least partially based on real D.C. individuals who we all know"he felt compelled to show intelligence officials, and they nixed some as too lifelike. And the part about getting rid of a president? MacKinnon recalls boozy talk during his Pentagon days about sidelining President Clinton. Despite his pedigree, the book takes on both political camps, which may explain the bipartisan lineup of those crowing about it, like former Sen. Bob Dole and James Carville.