They can veto congressional legislation. Doing so nearly always is sustained.
They can make law by executive orders even though nothing in the Constitution permits it. Presidents are constrained only by their own discretion. Otherwise they can do what they please.
Since December 8, 1941, they've waged war on their own. Doing so violates the Constitution's Article I, Section 8. Congress alone has that power. For over seven decades, members surrendered it illegally.
It's pure myth that governance is constrained by limited powers. It's closer to one-man rule. It's practically impossible to impeach scoundrels. No president ever was removed this way.
John Adams was the most distinguished constitutional theorist of his time. He said it would take a national convulsion to remove a president by impeachment. He was right. It never happened.
Venezuela's system is mirror opposite. Its Bolivarian Constitution was approved by national referendum. Doing so followed an initial one on whether to convene a National Constituent Assembly to draft a new document.
That's how democracy is supposed to work. It's never been that way in America. It never will under its current system. Over time, it's gone from bad to worse.
Venezuelans approved a model participatory social democracy. It's not perfect, but it's the real thing. Ordinary people serve as ombudsmen to assure other government branches comply with constitutional provisions.