Are they doing anything different from CERN?
As I understand it CERN does primarily high energy particle physics. Brookhaven I believe did participate in the analysis of the Higgs boson data produced by CERN. Our labs still have some of the best computational facilities even though we can’t produce data at those energies. We foolishly ceded that field to the Europeans when we canceled SSC.
I doubt if the “core work” of Brookhaven we be that harmed by anything Trump does. Getting it back to what its supposed to do and out of “pop science” like climate modeling would be good for the place.