Former Rep. Ralph M. Hall, who left Congress in 2015 as the oldest member at age 91 after losing a primary runoff after decades in office, died Thursday. Hall was 95.

A Democrat-turned-Republican, Hall was born on May 3, 1923, in Fate, Texas. He attended Texas Christian University and the University of Texas, eventually earning a law degree at Southern Methodist University.

He was in the U.S. Navy during World War II and was among the last members of Congress to have served in that war.

The Dallas Morning News and other Texas media outlets reported that Hall died of natural causes at his home.

After working as a business executive and lawyer, Hall began his career in public service as a judge in Rockwall County in 1950. He served in the Texas Senate from 1962 to 1972.

In 1980, Hall, then a Democrat, won his first election to the House. He defeated Republican business manager John Wright with 52 percent of the vote in an open-seat race. None of his re-election efforts had been as close since.

He reflected the conservative values of his rural northeast Texas district.

Following the 2000 Census and reapportionment, Republicans pressured Hall to switch parties and threatened to court serious opponents.

With then-President George W. Bush’s support, Hall eventually switched in January 2004. He was named chairman of the Energy and Commerce Subcommittee on Energy and Air Quality, where he worked on locally critical oil-related issues. When Democrats won the majority in 2006, he became ranking member of the Science and Technology Committee.

Hall married his wife, the late Mary Ellen Murphy Hall, in 1944. They had been married for nearly 64 years when she died in August 2008.

Hall was eventually defeated by Rep. John Ratcliffe in a 2014 primary runoff, losing his bid for an 18th term.