Gov. Bill Owens of Colorado is used to praise from conservatives. National Review dubbed him "the best governor in America" on its cover (illustrating a profile by John J. Miller). Conservatives lauded him for, among other things, his record of cutting taxes and spending. In recent weeks, however, Owens has announced a budget deal with Democrats that has some conservatives furious. Grover Norquist, the head of Americans for Tax Reform, accuses Owens of "betraying" taxpayers. The editors of the Wall Street Journal have zapped him. Owens's critics say that he is not only raising taxes, but weakening his state's constitutional...