Author bias note: I say this as someone who thinks Reagan is largely responsible for many of America's current problems in one way or another. And I personally doubt Trump will be good for the NSF's budget, and I get that Congress does appropriations and not the President speficially etc. Still.

The NSF isn't the only basic research foundation in the US, but the broader picture seems to tell roughly the same story: Total basic research funding has consistently done worse under Democratic Presidents since arguably Reagan: ncses.nsf.gov/pubs/nsf24332