US News ranks one of the universities in the United States.

One of the rankings of US News universities in the United States is Social Mobility Ranking, which is to see how many poor students a university enrolls and whether poor students can graduate well. I took a look at the top ten schools in California.
Of course not the ones you think of.
Riverside, Santa Cruz and Irvine ranked 1, 2 and 3 respectively, Merced 7, UC Davis and UCSB 9 side by side.
UCLA is also in the top 20, UCSD 21.

Part of the reason may be that California has a large population and that California’s finances are more supportive of vulnerable groups. Of course, it is also useful to charge more out-of-state tuition fees, especially for international students.
(It’s just that maybe you can’t get too many full-prize PhDs…)