Government is a Career Club.
If you want to run for city council, to "do the right things," you must first court the various govt. emplooyee unions.
Police and fire. You need to assure them, you are NOT in favor of cutting pay, benefits, pensions.
So from the start, you are precluded from the most significant reduction in cost.
In his time, Reagan knew this. He had been a union guy, himself.
He had some savvy advisors, guiding him with the fact he could only appoint a small number of political types, and was stuck with the career types.
A couple of such advisors were Howard Jarvis and Paul Gann, of Prop 13 tax limitation notoriety.
Their contribution was: government has inertia of its own. The most effective action, is reducing revenue. Just turn off down the spigot, which Prop 13 did do.
History wll record Trump did a lot by appointing judges, and cutting regulations.