A bit more about Bruce Rauner to fill in the gaps,
Bruce Rauner is, indeed, little-know in the general population, but he is very, very well know in the civic leadership, among the lakefront and north-shore voters, and carries a very big stick. He is a hugely wealthy venture capitalist, and his firm GTCR Golder Rauner is one of the power-house firms in a city with many power-house vc firms (GTCR just bout the American Stock Exchange). Rauner is fiercely smart (as is his equally respected wife, Diana Medley Rauner), and wouldn’t be snookered by anyone, least of all Daley. Rauner is very philanthropic, a centerist independent (he is close to both Jack Ryan and Andy McKenna), and when or if he wants to run for office, he will have immense advantages: his base will be the downtown business leaders, the lakefront and the north shore. From there he can use his money to build name recognition and a political operation. He also has one more advantage: his late business partner and mentor, Stan Golder, was beloved in the jewish community. Stan and his widow, Joan, treated Rauner almost like one of their children. The Chicago/north shore jewish vote will not forget this.
Obviously, anyone thinking of running for office after Hull is going to figure out the Daley game. And even in that, Hull’s contributions to Daley weren’t all in vain–Hull was able to play off what seemed like early Daley backing and use that to open even more doors. He has just had to change the strategy a bit.