United States Senator Charles E. Schumer, Democrat from Brooklyn, won re-election to a second term yesterday by an enormous margin, outpolling the former top vote-getter in the state, the late Senator Daniel Patrick Moynihan, and fueling talk that he may soon become a candidate for governor. Mr. Schumer defeated his opponents with more than 70 percent of the vote, a figure that exceeded Mr. Moynihan's record for a Senate election of 67 percent in 1988. His margin is doubly noteworthy because Mr. Moynihan's record was set in his run for a third term, after 12 years in the Senate, whereas...