John R. (Jock) McKernan, the new Republican congressman from Maine's 1st Congressional District, is only 34, but has been heavily involved in Republican politics in the state for some time. He will be filling the seat vacated by Republican Rep. David F. Emery, who was defeated in his Senate race.

McKernan, a Maine native, was elected to the state House in 1972, while he was still a law student, and in his second term was named the assistant Republican floor leader. He left the state legislature in 1976 to practice law full time but has worked in a number of GOP campaigns in the state, including Gerald R. Ford's 1976 campaign and President Reagan's 1980 general election race.

McKernan describes himself as a fiscal conservative, supports the Reagan tax cut and would vote for a balanced-budget amendment.

One major issue in his campaign was abortion. McKernan believes women should have the right to choose to have an abortion. His opponent, Democrat John Kerry, campaigned as being opposed to abortion.

Kerry was believed to be slightly ahead going into the election. But McKernan won with 51.2 percent of the vote.

Another major issue in his campaign was nuclear power. McKernan said he favored keeping the Maine Yankee nuclear power plant in operation but would not want a new nuclear plant in Maine.

Because many Maine residents earn their living as fisherman and a number of others work in defense-related industries such as shipbuilding, McKernan has said he would like to be assigned to the Merchant Marine and Fisheries Committee and to the Armed Services Committee.

McKernan was graduated from Dartmouth College and received his law degree from the University of Maine. He lives just outside Portland and will be representing the southern end of the state.