Every day there are discussions/disputes in the news about what powers the president of the United States has or doesn't have, and should or shouldn't have, to issue orders, make pardons (even possibly of himself!), hire or fire cabinet secretaries and heads of bureaus, agencies—and even declare war or take military action. The U.S. Constitution is somewhat clear about the powers of the branches of government, but a lot is left unsaid and unclear about these matters when the realities of actually governing have come up through the decades and centuries. In my opinion, the executive branch—the presidency—has always had too much power, especially when you consider the extra powers that have been subtly (and not so subtly) given (surrendered) to it by Congress over time, most glaringly concerning war-making powers.
The president should never be able to fire or hire anyone in any office who could conceivably investigate or accuse/charge (or fail to do so) him or her, or anyone working for him or her, with misconduct. The director of the FBI and other federal law enforcement and security officials should be chosen and monitored through means other than presidential nomination and later approval or disapproval—or firing. Likewise for the attorney general, an office that I think should be popularly elected or what have you, a person who should remain totally independent of presidential power. The president should clearly have no right to pardon himself, ever, and the president should be subject to criminal charges, trial, conviction, and punishment even while in office. There should be no immunity just because one holds the highest office. Otherwise, we creep dangerously toward possible dictatorship.
I think we need a radically new and more humane, civil-democratic rights oriented and fully detailed Constitutional overall, one that spells out rights and protections for people and puts way more direct power in the hands of the people. Thomas Jefferson once said that we should have either a new Constitution or a revolution every 20 years. That may be pushing it, but we are way overdue for a progressive re-write. We can start by limiting the powers of what has become our "elected king"—the U.S. president.