Most of the nation's bachelor's students attend what are often called "comprehensive universities," public institutions that primarily enroll students who live near the school and educate their students chiefly for jobs in the local economy. Relatively little research focuses on these institutions as a group, and therefore not much is known about these campuses, especially regarding their role in promoting social mobility. Using data released in 2017 by the Equality of Opportunity Project, the author shows that over half of the low-income students enrolled at the 307 comprehensive universities in his sample reached the two highest quintiles by their early 30s. However, he documents great variation in the rate of upward mobility across these institutions, even after controlling for selectivity, funding levels, and the student body's academic qualifications. Most comprehensive universities are classified by "Barron's Profiles of American Colleges" as "competitive," accepting between 75 percent and 85 percent of their applicants. Within that category, the percentage of students who achieve upward mobility ranges from around 30 percent to over 70 percent. For "less selective" comprehensive universities, as classified by "Barron's," the range is equally large (from 30 percent to 68 percent). This report investigates factors that might explain such variation in mobility rates. It finds that the factor most closely associated with higher mobility rates is college graduation. The report concludes with a discussion of several ideas to potentially increase graduation rates at comprehensive universities.