A Milwaukee-area inventor would like to make Milwaukee a streetcar suburb of Chicago. Just build a Shinkansen style track above existing railroad tracks. That's fine, if private money comes up with it. (Call me skeptical.)
I stick to my view that providing a track structure suitable for 125 mph running with diesel trains and bringing Chicago within an hour of Milwaukee by rail is the more cost-effective way to go. Unfortunately, the good people of Glenview aren't yet ready for that.