Malcolm Wallop, a three-term Republican senator from Wyoming who was a leading conservative voice during the Reagan era in fighting for space defense and a tough anti-communist policy in Central America, died Sept.  14 at his home near Big Horn, Wyo. He was 78.

Kerrie Kimmel of the Kane Funeral Home confirmed the death but did not disclose the cause.

Sen. Wallop served in the Senate from 1977 to 1995 and had an unusual résuméfor a Western politician. A member of a third-generation Wyoming pioneer family, he graduated from Yale University, and his grandfather served in the British House of Lords.

Former vice president Richard B. Cheney and former senator Alan K. Simpson served with him in Wyoming’s congressional delegation in the 1980s.

“Malcolm was sort of the spark plug, he was the senior guy, and Al and I were delighted to work with him,” Cheney, who was then the state’s representative at large, said in a telephone interview. “My record and Malcolm’s record were pretty similar in terms of how we voted on the issues.”

Sen. Wallop’s 18 years in the Senate included time as the top Republican on the Energy and Natural Resources and Armed Services committees.

Simpson said that Sen. Wallop’s seniority on Senate committees as well as the senior party-leadership positions of himself and Cheney made the Wyoming delegation into a powerful political trio.

“It was said that was the most powerful delegation pound for pound in Washington,” Simpson said. “And I’m sure we didn’t let it go to our heads.”

Sen. Wallop gained a significant victory when President Ronald Reagan began pushing the spaced-based antimissile defense concept. Sen. Wallop was among a group of conservatives who had espoused the plan for years before Reagan came to support it.

Key legislation that Sen. Wallop helped pass included an energy bill in 1992 and major portions of Reagan’s tax cuts in 1981. In 1984, Sen. Wallop helped create the Wallop-Breaux Trust Fund, an account used to finance state fisheries and boating programs. The fund uses money raised through special fees and taxes on fishing gear and motorboat fuel.

Sen. Wallop’s campaign style caused amusement in the state but won him elections. When he first ran for the Senate, he ridiculed a federal regulation mandating a specific number of portable toilets for farm workers with political advertisements showing a cowboy riding across the range with a portable toilet on top of a packhorse.

Sen. Wallop didn’t seek re-election in 1994, but he remained politically active as founder of the conservative Frontiers of Freedom Institute think tank.

Malcolm Wallop was born Feb. 27, 1933, in New York City and grew up on his family’s 3,800-acre ranch in Big Horn.

His British-born grandfather, the eighth Earl of Portsmouth, lived in the United States for nearly 40 years before returning to England in 1933 and had served two terms in the Wyoming legislature.

Malcolm Wallop graduated from Yale in 1954 and then served three years in the Army before focusing on ranching.

Before winning election to the U.S. Senate, he served two terms in the Wyoming House and one term in the Wyoming Senate.

His U.S. Senate tenure included several prominent assignments. He was chairman of the Select Committee on Ethics from 1981 to 1983, during the trial of Sen. Harrison A. Williams Jr. (D-N.J.) on bribery charges stemming from the Abscam scandal.

In 2000, Sen. Wallop’s wife, the former French Carter Gamble Goodwyn, filed for divorce after 18 years of marriage. The U.S. Supreme Court in 2004 allowed him to keep his family ranch, then valued at $4.6 million.

He was married four times in all. He is survived by his wife, Isabel, and four children.

Sen. Wallop was unapologetically conservative as a Republican, a position that sometimes drew ire from members of his own party.

“Too many Republicans prefer to be a Democrat Lite,” he said in a speech at the Cato Institute in 1994. “As any beer connoisseur can tell you, Lite is a tasteless, repugnant concoction.”

— Associated Press

Staff writer T. Rees Shapiro contributed to this report.