PUNCHY BYLINE: The first time he practiced journalism, he was sued by Adolf Hitler. Former Sen. Alan Cranston (D-Calif.) has taken up pen and paper again, and his roundhouse swings at a longtime foe, Senate Minority Leader Bob Dole (R-Kan.), have drawn some hard counterpunches. . . . Writing in Rolling Stone magazine, Cranston calls Dole the "prince of legislative darkness," saying his fierce partisanship "spells big trouble in the Senate" for President Clinton. "The good news is that Dole isn't President. The bad news is that nobody's told him," Cranston wrote. . . . Cranston uses anonymous sources (the kind he denounced when he was enveloped in the Keating Five scandal) to back his charge that Dole is a "slash-and-burn" opportunist. A "GOP congressman" likens the senator to horror-movie villain Freddy Krueger, and a "Senate colleague" says Dole, who suffers from a World War II arm wound, is "striking back at a world of people who were not wounded." . . . In a statement, Dole calls the article "fiction," noting that he has supported Clinton on aid to Russia and the proposed trade pact with Canada and Mexico. Dole added: "I feel sorry" for Cranston, who "left the Senate in disgrace" after serving as "a highly partisan liberal Democrat. . . . He didn't win any popularity contest in the Senate, and now I better understand why."