From Kevin Williamson at National Review, Pruning the Presidency:

The Left has aggrandized the presidency because it wishes to rule the country administratively rather than through the clunky process by which lawmakers go about making laws in a thoroughly unscientific and unprofessional fashion. That we might return to such a state of affairs is the dread that currently keeps American progressives up at night: Writing in Vox, that great dispassionate explainer, Ian Millhiser raises the alarm that Brett Kavanaugh seems to be taking a more restrictive view of the nondelegation doctrine, which is to say, that the Supreme Court might be poised to insist that lawmakers go back to writing the laws instead of sending memos over to the White House instructing the bureaucracies to write the laws and call them “regulations.” The headline: “Brett Kavanaugh’s latest opinion should terrify Democrats.”

Various progressives have argued over the years that we should extend presidential terms and expand presidential powers in order to make governance more effective, which in this case is a near-synonym for unopposable. They look longingly at the parliamentary systems under which prime ministers enjoy both legislative and executive power, and toward nondemocratic bureaucracies in which empowered expert managers rule by technocratic fiat (Thomas Friedman’s “China for a Day” fantasy). This is partly because they are confident that they will get their way more often under such procedures — look at the nation’s universities and corporate human-resources departments if you doubt that progressives know how to work a bureaucracy — and partly because they maintain a delusional faith in what we are expected to call with straight faces “political science.” They adhere to rationalism, in Michael Oakeshott’s sense of that word, and hence must regard democratic compromises (along with checks and balances and formal limits on state power) as deviations from the optimum policy they believe they can deduce logically.

The remedy for this, we are told, is “political,” meaning that misbehaving presidents can be defeated at the polls or, if necessary, impeached and removed from office. But surely these cannot be the only controls on the president. Though norms and traditions are fine, we need some hard-and-fast rules about what presidents can and cannot do and some clarity about our legal and constitutional basis for those rules. And most of all, we need a presidency that is reduced, one that is put back in its constitutional box and limited to its constitutional role: seeing to the faithful execution of the laws.

But to take the presidency down a peg, Congress has to step up and reclaim its institutional self-respect. That is not the same thing as self-importance — the only commodity of which Congress is running a long-term surplus.
Another excellent piece from Kevin Williamson.  The rise of presidential powers tracked the progressive tilt in American politics for the last century. Much of this power was acceptable as long as progressives of either party were in power, but this compromising of constitutional restraints was blind to the possibility of this power being in the hands of their opposition.  Means do matter. The tools of defeat are prepared by the shortsighted.
Both sides refuse to re-examine the proper role of the presidency, and focus on the president in power.  It may seem unrealistic to return to constitutional norms, but the alternative seems to be an escalation of the bitterness of our politics.