The Midwest cluster of cities which include Chicago, Cleveland, Indianapolis, Minneapolis, St Louis, Columbus, and Detroit, have an extremely similar density and distance distribution compared to France, where high speed rail is incredibly successful. We could have successful high speed rail nearly everywhere in the US with a possible exception of the rocky mountain regions. I wish this density trope would die.

The real reason we don't have high speed rail is that right of way acquisition is ridiculously costly unless government is involved, and we don't trust our government to do it right. Probably justified, if urban rail costs are indicative.