Some universities rank those that are majoring in CS higher up in the registration chain, than those taking it for elective, those that are minoring in CS and those that are returning back to school. This means multitudes of students face difficulty in getting into their 100 & 200-level courses. At my school it isn't uncommon to have three sections of 300 students each in the 101 class and 300+ people vying for limited seats in the 200-level class. One of the sophomore level classes expanded their seats to nearly 500 people, but that doesn't solve the problem of getting into the upper division courses that are capped at 150 people. Schools are leaving out a large population of students registering for these courses, which may include first generation students, women and minorities. Even the 100-level courses can nearly be impossible to register for at this point.