When Marco Rubio declared his candidacy for U.S. Senate earlier this month, he said his campaign wasn’t “against anyone or anything.” On the Spanish language Univision Network, however, his tone was as different as the idiom, saying he was interested in combating “the kind of American Socialism that they want to establish in the U.S.” Last Friday night in Tampa, I asked the former House speaker, who will compete head to head against Gov. Charlie Crist for the nomination to succeed Mel Martinez in the Senate next year, what exactly did he mean by that? “The tax plan that the...