You want to know what predicts long-term trends? Public mood.
There was no trend of more passenger rail in Wisconsin, there was little public mood for it, and frankly I was positively surprised when the Madison project got off the ground. Walker of course sabotaged it deliberately by breaking contracts, which is actually unusual (though it is what you expect from someone most of whose senior staff has been convicted). Even so, the project will probably be back eventually because the city of Madison wants it, and everyone's staring at next-door Illinois.
(Why do I say there's no trend in Wisconsin? The existing Milwaukee service and the existing Metra service to Kenosha both predate 1970. Attempts to increase frequencies have failed. Attempts to extend Metra service have failed. Attempts to build a Milwaukee Streetcar have not succeeded yet. The extension of the Hiawatha Service to Watertown in '98 was started and then cancelled. The only successful projects so far are the miniscule Kenosha streetcar and the minimalistic Milwaukee Airport station.)
By contrast, there is a trend of more passenger rail in Minnesota, and an increase in "mindshare". There wasn't before Jesse Ventura got the Hiawatha Line opened, but there has been since then, and it hasn't stopped. Projects are going to keep getting funded and built. And intrastate politics is going to mean that one of the intercity projects is going to get built relatively soon (next decade or so), due to the usual way the arguments play out when everyone starts being pro-rail: after the first several urban lines, people start saying "Why can't we get to other cities?". It is possible that Chicago-Twin Cities will be pushed onto the back burner repeatedly if *another* project successfully gets funded like St. Cloud or Duluth or Rochester or something -- but that seems truly unlikely.
If not, and if a standalone Chicago-Twin Cities service turns out to be relatively cheap (as it is likely to be), a standalone Chicago-Twin Cities service will probably be the sop thrown to intercity rail.
Duluth service (before Chicago service) was always a longshot and was maintained purely by Oberstar's advocacy -- but you'll notice he didn't manage to get it done despite being in office for decades. Politicians make a difference, but politicians are swayed by the public mood.
And I guess you don't think Minnesotans give a damn about whether they can get to Chicago by train. Well, I think the percentage who give a damn has been slowly edging up and will continue to do so. This question could only be settled by polling which I haven't been able to find.
You speak of money. Well, look how much money actually has been appropriated for passenger rail in Minnesota. Yes, you've blown vast quantities on stadia, but you've also actually put meaningful amounts into passenger rail. The fact that most of it has happened at the county level doesn't really change the long-term implications of that, politically. By contrast, Iowa seems unable to spend a dime.