As much as people like to rail on Roger Penske, they'd be there if he still owned it. You can throw Auto Club and Nazareth into that mix as well. He's the main reason Detroit exists and as much as some of the tree hugging locals up there want that race gone, their island has benefited tremendously from having that event.

They all became ISC properties during the split. Michigan seems to have nothing to do with them, has even said they aren't a focus. Auto Club couldn't even entice a rat with free pizza to come to a race and we all know what has happened to Nazareth.