Well maybe I'm being a bit dramatic, but why would you establish a policy of limiting drivers licenses only to green card holders and US citizens? Legal immigrants on visas (such as H-1Bs, F-1 students, J-1s, etc.) can no longer get drivers licenses in Michigan.
So if you're a multinational corporation operating in Michigan, you need to immediately begin thinking about moving your operations to another state. And all those American workers at your plants are just going to have to deal with it. If you're a US company in Michigan and think you're going to be able to recruit top global talent, sorry folks. And if you're a premiere university planning on attracting top students, researchers and scholars, you're out of luck.
Congrats Michigan! </sarcasm off>