Dr. Kitzhaber began his political career serving in the Oregon House of Representatives from 1979 to 1981. In 1980, he was elected to the State Senate, where he served from 1981 to 1993, and as President of the State Senate from 1985 until 1993. In 1994 he was elected Governor of Oregon, and served in that position from 1995 until 2003.
As Oregon Senate president he was instrumental in the creation of the state's government-funded healthcare plan. He won the Democratic Party nomination for governor in 1994 when the Democratic incumbent, Barbara Roberts withdrew from the race in January of that year when, after voters refused to pass a sales tax to fund the Oregon health plan, she was forced to break her campaign promise not to cut spending. Kitzhaber won the general election with 51% of the vote, defeating the Republican candidate Denny Smith who received 42% of the vote. He won reelection in 1998 with 63% of the vote. His Republican opponent, Bill Sizemore, received 31% of the vote. Oregon's constitution prohibited Kitzhaber from seeking a third term in 2002.