In 1971, he managed the successful Michigan House of Representatives campaign of fellow student and future Michigan governor John Engler. Posthumus was elected to the Senate in 1982 and became majority leader in 1990, when Engler was elected governor. His 1982 campaign was managed by Saul Anuzis. Posthumus was the longest serving majority leader in the history of the Senate.
Posthumus joined Engler on as his running mate and candidate for lieutenant governor in 1998[4] and went on to serve in that post for four years. He was the Republican nominee for governor in 2002, having defeated Joe Schwarz in the Republican primary, but lost to DemocratJennifer Granholm in the general election. He joined Compatico in 2005 and became the chief executive officer in 2006.
Posthumus married Pamela "Pam" (née Bartz) in 1972. They had four children together, and seven grandchildren. Pam died of cancer on August 18, 2010.[7] Posthumus married Beth Ann (née Mihlethaler) Fogg on September 24, 2011.[8] Dick's son, Bryan, is a Michigan state representative, and advocate for Alcoholic's Anonymous and Dick's daughter, Lisa, is a Republican member of the Michigan House of Representatives.[9]
