There will be no organized union boost behind a single candidate in Saturday's Democratic caucuses in Michigan, a state where union members can wield more clout than almost anywhere else. While national labor leaders are assuming Michael Dukakis will be the eventual nominee, they are prevented from endorsing him by what appears to be growing rank-and-file support for Jesse Jackson, who has gotten more union votes than any of the other candidates in primaries so far. Richard Gephardt also has considerable union support. None of the Democratic candidates appears to have won the hearts _ or votes _ of a majority of the state's 750,000 rank-and-file union workers, nearly half of them members of the United Auto Workers.
