Incumbent Democratic Governor of Michigan Jennifer Granholm was re-elected with 56% of the vote over Republican businessman Dick DeVos and three minor party candidates.

[2] As of 2022, this is the last time the Democratic candidate for Governor carried the counties of Keweenaw, Houghton, Ontonagon, Iron, Dickinson, Menominee, Delta, Schoolcraft, Mackinac, Luce, Chippewa, Mason, Lake, Oceana, Van Buren, Cass, Calhoun, Monroe, Jackson, Tuscola, Shiawassee, Montcalm, Ionia, Gratiot, Midland, Clare, Gladwin, Roscommon, Ogemaw, Iosco, Arenac, Crawford, Alcona, Alpena, and Presque Isle.

A political unknown, Louis Boven, tried to challenge him in the primary, but failed to meet Michigan election requirements to get on the ballot.

[citation needed] DeVos selected former State Representative and Oakland County Clerk Ruth Johnson as his running mate on August 14.

DeVos criticized the Single Business Tax, high unemployment, and job outsourcing which occurred during Granholm's first term; Campbell assailed the $12 billion taken from Michigan's taxpayers and appropriated to the military siege of Iraq (which he calls "Duh-bya's Folly") and advocated for a local currency, independent of the U.S. dollar which he and running mate David Skrbina say is in imminent jeopardy of collapse.

[29] Granholm and DeVos appeared together October 12 at the Detroit Economic Club in which each candidate delivered their job plans, which was described as a debate at the event itself, even if it wasn't officially designated as such.

Detroit News pollster Ed Sarpolus indicated that there was no clear winner in the debate, but Bill Rustem, senior vice president of the nonpartisan policy firm Public Sector Consultants in Lansing, favored Granholm.

[32] The consensus of pundits Bill Ballenger, George Bullard, Kathy Barks Hoffman and Rick Albin and capital correspondent Tim Skubick, speaking on the October 6 WKAR-television program Off the Record,[33] was that both DeVos and Granholm emerged losers, losing 2 and 4 percentage points' support after the event.

[35] No major gaffes came out in the debate, but one minor zinger was made by Granholm about DeVos' investment in Alterra, a chain of nursing homes which sexually abused and neglected its patients.

DeVos was more aggressive than before, declaring that Granholm had lied about him having a controlling stake in Alterra Health Care, an elder-care company that suppressed information about the abuse of residents by its employees.

Unlike the previous debates, this one had an invited studio audience of 30 undecided voters, some of whom asked questions to the participating candidates.

[43][44] Granholm and DeVos sparred on various issues including college tuition, Canadian trash, business taxes, President Bush and negative ads,[45] while Creswell supporters picketed outside.

DeVos' lead eroded when Granholm started running ads; meanwhile, Granholm built up a lead as voters found out more about the candidates culminating in the three debates, and as political fortunes soured for Republicans across the country due to a massive backlash against then president George W. Bush and fatigue over the continuing War in Iraq.