Former Rep. John Rhodes, the 15-term lawmaker from Arizona who helped lead House Republicans through the Nixon Watergate scandal, lost his fight with cancer Sunday night. Rhodes died at his home in Mesa, Ariz., at age 86.

The Harvard-educated lawyer who rose to become a four-term Minority Leader will probably be best remembered as one of the Republican leaders who informed President Richard Nixon that his support in Congress had crumbled and that impeachment for the Watergate cover-up was inevitable.

When Rhodes, originally one of Nixon’s staunchest allies during the scandal, announced he would vote for impeachment following the release of the president’s Oval Office tapes, it became a signal to many that the Nixon administration was doomed.

Years later Rhodes would say that turning his support against Nixon was one of the hardest decisions of his life, but that for government to work no man could be above the law.

Rhodes retired from Congress in 1983 and returned to practicing law for the Richmond-based firm Hunton & Williams. In 2002 he became one of the two original recipients of the Congressional Distinguished Service Award.

“John Rhodes was a political giant who made all Arizonans proud,” Sen. John McCain (R) said of his late fellow Arizonan in a statement released Monday. “John’s integrity and political courage were instrumental in helping guide our nation through the Watergate crisis. … Arizona, and indeed America, is [a] better place because of John Rhodes’ leadership.”