THE UNITED States may be turning a corner in presidential politics. Although the election itself is more than a year away, the latest reports to the Federal Election Commission show that a wealthy oligarchy of donors has come to dominate campaign finance, particularly in the crowded Republican contest. Fewer than 400 families are responsible for almost half the money raised in the campaign so far, according to an analysis by the New York Times. This class of wealthy patrons, some with new fortunes and others of long-standing, is throwing money into campaigns, not of all which will end happily. But the preeminence of this clan of tycoons so early in the season is not a good sign.