Three general reasons for realignment
1. similar institutions
This could be as obvious as the Wisconsin Intercollegiate Athletic Conference, a collection of state schools in the state of Wisconsin, or the University Athletic Association, a group of research institutions across the country who are also members of the Association of American Universities. These conference affiliations can find commonality in admissions practice, perceived academic standing, or size of the institution. In addition, these are not decisions made by faceless bureaucrats at schools – they are made by human beings, with human emotions and human desires for connection. Sometimes, a conference membership decision may come simply down to a college or university president wanting to fit into another group.
2. geographic proximity
Depending on the part of the country, it may be more prudent for a school to affiliate with schools within a shorter travel distance. This generally leads to less missed class time for student-athletes, lower costs in terms of hotel stays for teams and other benefits in terms of costs. A school may have to balance the geography with that desire to align with other like-minded institutions.
3. the ability to win conference championships
A team in a large conference may find it easier to make the NCAA postseason in a sport if it moves to a smaller league, or, one in which it thinks it may have better success compared to its conference peers. Moves based solely on getting into a so-called easier conference have a mixed track record in working out.
Mississippi Valley State @ 
Utah 
.
