During his final year in law school, Magruder ran for a seat in the Oregon House of Representatives and won.

In the Democratic primary, Magruder defeated the seven-term incumbent, Wayne Turner, by a margin of more than a two-to-one.

[1][6][7] After the 1971 legislative session, the House of Representatives was re-districted and Magruder's home in Clatskanie became part of District 1.

In a re-match of the 1970 Democratic primary, Magruder beat former state representative Wayne Turner, receiving 61 percent of the vote.

Because of his conservative voting record in the House of Representative, his Republican opponent was endorsed by the AFL–CIO and the Oregon Education Association.

However, Magruder's conservative fiscal views put him at odds with House liberals including the Speaker.

This on-going conflict encouraged further cooperation between conservative Democrats led by Magruder and the Republican minority in the House.

While the speaker was not removed from office, the Rules Committee took control of virtually every aspect of House operations.

As a member of the Rules Committee, Magruder played a key role in setting the legislative agenda for the remainder of the 1977 session.

[2][5][32] The House Speaker, Phil Lang, said: His great concern for fiscal responsibility and his commitment to the concept of a citizen legislature attests to his wisdom.

His leadership for the rural and farming areas of our state, along with his keen mind and wry wit, will be sorely missed by his colleagues.

[32]Oregon's governor, Robert W. Straub, praised Magruder, saying: He was a man of high ability and strong independence.

[32]On June 22, 1978, a memorial service for Magruder was held in the House chamber at the Oregon State Capitol.

As a result, Brown faced a newly appointed incumbent Democrat, Caroline Magruder, in the 1978 general election.

[35] In the November election, Mrs. Magruder beat Brown, taking her son's seat in the state legislature.

[19][20] Every year, Oregon State University awards the Dick Magruder Memorial Scholarship to a number of students majoring in veterinary medicine.