First of all, realistically the Casino will probably never be built. The city of Grand Forks and UND are a seperate entity. UND is huge for the city but it is not the only thing. Maybe UND has to much pull in Grand Forks, and at certain times it hinders GF's growth in certain aspects.
A minor example is every year Grand Forks gives money to UND for recruitement etc, but a couple years ago I believe UND wanted more (or just the same), and GF was like "thats ok you guys seem to be doing pretty good already, maybe that money can go to lower taxes or repair roads." A larger Grand Forks would mean a larger enrollment, more fans at football, hockey, and basketball games for UND.
BTW, my mom works at UND.