Former US Senator James Buckley, a premier conservative voice in Washington in the 1970s who successfully challenged limits on spending by political candidates while championing student privacy rights, died on Friday in Washington at age 100, the Washington Post reported.
His son Peter Buckley confirmed the death but did not provide a specific cause, the newspaper said.
Buckley served in a high office in all three branches of the US government and was a hero to many in the conservative movement, but his career was overshadowed by his brother William F. Buckley Jr., the renowned conservative commentator.
He served a single term in the Senate from New York from 1971 to 1977 under the banner of the Conservative Party - winning a three-way race that ousted an incumbent Republican.
In 1975, Buckley led a court challenge to a campaign finance reform law imposing limits on the amount of money political candidates could spent on campaigns and the amount individuals could donate to candidates. The law was passed by Congress after the Watergate corruption scandal that in 1974 led Richard Nixon to become the first US president to resign.