[AskewEgret]

New York to Chicago via Toronto and Detroit is certainly not the most direct route, but it does make a lot of sense in the context of what is already in place.

VIA Rail advertises that its Toronto to Windsor service is a great alternative to driving and flying. It is 1 hour slower than flight and about equal to driving. Surely they can make some good improvements. EDIT - I just discovered that Ontario has committed to bring the Toronto to Windsor line to 200 km/h by 2025 and 300 km/h by 2031.

A brand-new bridge between Windsor and Detroit has already been approved. Canada is paying for 100% of it, why not add rail capabilities (like the Øresund bridge between Sweden and Denmark)?

The Detroit to Chicago Amtrak line runs at > 100 mph for almost the entire length already (paid for by the "car-friendly" state of Michigan). The major bottlenecks are two counties in Indiana that Pence hates. With him in Washington, he might still find a way to block construction, but then again he might be too busy to get involved in such piddly things anymore.

So basically, you just need to find a good way to speed up the current New York to Toronto Amtrak, which is 12.5 hours to go 350 miles!

[jcranmer]

Putting rail over the new Detroit/Windsor bridge isn't a particularly good idea (you're not really connecting the stations), but actually crossing the river (neither the Saint Clair nor the Niagara) isn't the problem. The hard problem is solving the border control issue.