Answer is the power to raise taxes
This is a tricky one because the president does address taxes in his budget, but it is congress that has that expressed duty.
“Article I, Section 8 of the Constitution gives Congress the power to "lay and collect taxes, duties, imposts and excises, to pay the debts and provide for the common defense and general welfare of the United States.” copied from the internet.
Now we know the president says in his oath he is to carry out the laws. We also know the President nominates federal judges. So I’m going with Congress has the power to raise taxes.