Mathias Joins Republican Senators Not Seeking Reelection in ’86

Republican Sen. Charles McC. Mathias Jr. of Maryland announced Friday that he will not seek reelection next year so that he can spend more time with his family--a decision that boosted Democratic hopes of capturing his seat and regaining control of the Senate.

He was the third incumbent Republican senator since last month to drop out of contention for another term, following Paul Laxalt of Nevada and John P. East of North Carolina.

Republicans have a 53-47 advantage over Democrats in the Senate, but 22 seats now controlled by the GOP will be at stake in the 1986 elections, compared with only 14 Democratic seats.

The withdrawal of Mathias, 63, from the race opens the way to a possible bid for the Republican nomination by Jeane J. Kirkpatrick, the former U. N. ambassador and former Democrat who is now a favorite of GOP conservatives. Other potential candidates are Donald Devine, former head of the Office of Personnel Management, who also would have strong conservative support, and Maryland Rep. Marjorie S. Holt, who has announced plans to retire from the House.

Among potential Democratic contenders for the seat are Maryland’s Reps. Barbara A. Mikulski and Michael D. Barnes, as well as Gov. Harry Hughes.

Mathias, at a news conference where he was warmly applauded by friends and supporters, said: “It seems to me that the season has arrived to shift to a new field of activity, while retaining many of the interests and concerns that have been the focus of my life.”

A member of the once-influential group of liberal Senate Republicans since he first was elected in 1968, Mathias has sometimes seemed out of step with the now-dominant conservative wing of his party.

He has prided himself on his championship of civil rights and last June helped block the promotion of Assistant Atty. Gen. William Bradford Reynolds, architect of the Reagan Administration’s civil rights policies.