Having learned that Carnegie Mellon has waitlisted me, (no, it didn’t send out acceptances to every physics PhD applicant before releasing waitlist decisions) and that CMU sent out offers to American applicants first, I have to conclude that CMU became more protectionistic than I would have expected out of a private school, and at least as much so as Minnesota, if not more. In fact, protectionism in private schools is often tied to the presence of military-funded projects (Johns Hopkins applied physics, for example) or otherwise national security-sensitive.
That said, with a once-erroneous personal statement (contained a mention to an astrophysical sciences department; yes, CMU does some astrophysics, but it became painful to me once I realized that I didn’t do all the modifications required from the SOP at Princeton, and there was the glaring absence of the people of interest) and no connections whatsoever, I managed to get a waitlist out of a particle cosmology group that had almost as much cosmological (meaning in-subfield) prestige as UPenn, then it gives me some hope for UPenn itself, where I actually have connections and a personal statement that is fully accurate.
And, as I have been told that my stipend would be $2,375/month, I still have some hopes that I will get admitted at CMU off the waitlist. In years past, they did get a few people off the waitlist, even particle cosmologists. Now I am torn between visiting Carnegie Mellon in an attempt to get in off the waitlist, or visiting Minnesota, which could end up becoming my final decision.