The authors of the Constitution separated powers for a reason

"Donald Trump decided [last week] to lift, temporarily, most of his arbitrary tariffs* ... his personal decision ... his whim ... And his whim could bring the tariffs back again.

    “The Republicans who lead Congress have refused to use the power of the legislative branch to stop him or moderate him, in this or almost any other matter. ... No one, apparently, is willing to prevent a single man from destroying the world economy, wrecking financial markets, forcing this country and other countries into recession if that’s what he feels like doing when he gets up tomorrow morning. ...
    "After arguing about how to limit the powers of the American executive, the writers of the Constitution decided to divide power between different branches of government. More than two centuries later, the system created by that first Constitutional Congress has comprehensively failed. ... The people and institutions that are supposed to check executive power are refusing to restrain this president. We now have a de facto tyrant who thinks he can bend reality to his will.

    "In recent years, many people who live in democracies have become frustrated by their political systems, by the endless wrangling, the difficulty of creating compromise, the slow pace of decisions. Just as in the first half of the 20th century, would-be authoritarians have begun arguing that we would all be better off without these institutions. ... In the United States, a brand-new school of techno-authoritarian thinkers find our political system inefficient and want to replace it with a ‘national CEO,’ a dictator by a different name.⁠
    “But in the past 48 hours, Donald Trump has just given us a pitch-perfect demonstration of why legislatures are necessary, why checks and balances are useful, and why most one-man dictatorships become poor and corrupt. ... If the Republican Party does not return Congress to the role it is meant to play and the courts don’t constrain the president, this cycle of destruction will continue and everyone on the planet will pay the price.”⁠

~ Anne Applebaum from her op-ed 'This Is Why Dictatorships Fail'

* Rob Tracinski, today: "After the markets crashed for a few days, and the bond market made some particularly ominous noises, Trump suddenly pulled back his disastrous tariffs to mere Smoot-Hawley levels, and apparently just today, his people figured out it would be unpopular to put massive tariffs on laptops and iPhones from China, so they exempted those products."