[3] When Senate successor Loyd Coleman was forced from office upon a criminal conviction in April 1987, Mitchem jumped into the special election and won handily in the primary, and by a 2-to-1 margin over Republican Nell Burton Skidmore.

With the growing strength of the Alabama Republicans, he faced opposition during his last terms in 1994, 1998, 2002 and 2006, with a declining, but respectable, percentage of the vote.

He then resigned from the position on February 5, 2009, per a prior agreement to allow a vote on Rodger Smitherman to succeed him for the remaining two years of the session.

As of 2010, Mitchem was serving in his 36th year in the Alabama Legislature, then the longest-serving member (with a 5-month gap of service in early 1987).

In 1980, Mitchem was appointed by then-Governor Fob James, Jr. as Chairman of the Alabama Governor's Commission on Physical Fitness, serving in that capacity for 28 years.