Rock-ribbed Republican Vermont, home of Calvin Coolidge, may have two Democratic senators come January 1982. Philip H. Hoff, the only Democratic three-term governor in the state's history, is quietly readying to challenge GOP incumbent Robert T. Stafford. Hoff , a Burlington, Vt., attorney who held the executive chair from 1963 to 1968, has always been a strong vote-getter in the state.
Vermont's other Senate seat is safely held for the Democrats by Patrick Leahy. Leahy won a second six-year term last year at the same time Ronald Reagan was carrying the Green Mountain state in the presidential election.