For reference, the distance between Minneapolis and Chicago is about 400 miles.
If the Amtrak schedule [0] is strictly adhered to, the travel time is ~7.75 hours. Current prices are ~$116 roundtrip.
Google Maps says the estimated time by car (assuming no traffic) is ~6.25 hours. At ~30 miles/gallon at $2/gallon, the cost of a roundtrip for just gas would be ~$53.
A roundtrip, non-stop flight lasting ~1.5 hours each way can be had for ~$80~$175 with the passenger's choice of at least 10 distinct flights/3 separate airlines.
I like rail. But it's clear that there's not a market fit for rail between Minneapolis and Chicago without massive subsidies. A car is faster and cheaper. A plane is much faster and about the same price. Both car and planes are strictly more convenient.
[0]: https://www.amtrak.com/content/dam/projects/dotcom/english/p...