James Jeffords, the former Vermont senator who controversially left the Republican Party in 2001, died Monday at a military retirement center in Washington. He was 80 years old.
The Burlington Free Press first reported the news.
Jeffords is best known for his high-profile departure from the GOP and decision to caucus with the Democrats in 2001. His move to become an independent shifted the balance of power in the chamber, which had been 50-50 Republican and Democrat.
One of the biggest factors behind the switch was the GOP's refusal to fully fund the Individuals with Disabilities Education Act, a bill he voted in favor of as a member of the House back in 1975.
The Washington Post called Jeffords' departure "one of those rare singular moments" when one lawmaker could change the arc of politics, adding it: "served to highlight the feud between the still-dominant conservative wing and the increasingly marginalized moderate faction of the Republican Party."
In 2005, Jeffords announced he would not seek a fourth term in office, bringing an end to his 18-year run in the Senate. Jeffords cited both his and his wife's health problems as a factor in his decision.
His wife Liz passed away in 2007. Jeffords is survived by his two children, Leonard and Laura.
This story contains images from Getty Images.