He just might, there is a lot of anger at the current Michigan governor over the Flint water crisis.  At the same time Trump did narrowly carry Michigan so a lot will depend on turnout.  A strong turnout usually favours the Democrats while a weaker turnout favours the GOP.  The GOP has a strong base in Michigan, particularly the western part of the state, however the state is 14% African-American who generally vote Democrat in massive margins, but turnout is unpredictable as well as they do have a number of colleges so millennial turnout is important as well.