That goes along with making new laws, this can all happen if Congress wants it to. While the concept is 3 co-equal branches in reality and in the writings, one of them is more equal than the others.
There's a lot of rules and norms and decorum but if 75% of reps and senators want something to happen Federally outside of new amendments they can do it. They can keep impeaching and removing Presidents until we get whoever in line they want. They can reduce or expand the size of the Supreme court, they can disband many Executive agencies because technically they still operate under a mandate from Congress.
Congress has a lot of power they just don't want to use it, usually for craven political reasons and the fact it is so wildly partisan, there is basically zero crossover so all those real power moves are just never in reach. There really does need to be reforms because the system as designed isn't quite set up to deal with politics today.