Bill Cohen was certain of one thing in June of 1974: The voters of Maine would not send him back to Congress. The 33-year-old Bangor mayor had been elected to the U.S. House of Representatives less than two years earlier but had done something unthinkable to many of his Republican colleagues and constituents: He’d voted to hold a president of his own party accountable to congressional investigators, opening a path that could lead to his impeachment. President Richard Nixon, who had fired the independent investigator probing possible White House involvement in breaking into the Democratic National Committee’s headquarters in the Watergate Hotel, had offered to give the House Judiciary Committee edited transcripts of tapes he had secretly recorded of some of his key conversations.