According to existing Supreme Court precedent, the president isn't able to impound funds which had been allotted by Congress (line item veto) [1], or fire the head of an independent agency for reasons other than allowed by Congress [2], it doesn't really seem like precedent has much weight amongst those in power today.

[1] https://supreme.justia.com/cases/federal/us/524/417/

[2] https://en.wikipedia.org/wiki/Humphrey%27s_Executor_v._Unite...