I don't have a problem with educating foreign students, only those who have no intention of staying here, or those who won't be allowed to stay here. Top universities can stay top when we educate only those foreign students who can both be allowed to stay and have stated their intention of staying.
Students are not a drain, even if tax payers fund them.
They spend money in the local economy. They help with competition and keeping standards up. They (as others have said) take back useful soft-power propaganda to their home countries.
The ones who leave are a drain compared to students who spend money in the local economy and pay US taxes the rest of their lives. We shouldn't push them away or educate the ones who have no stated intention of staying here. There will still be plenty who leave anyway to propagate propaganda.