Trump has cloaked his tariff proposals in populist rhetoric, but they represent cronyism of the highest order, providing concentrated benefits to narrow political interests while imposing much larger costs on the general public. It would be difficult for such a proposal to pass muster in Congress, whose members represent Americans with a vast array of contradicting interests.
Setting factions against each other to make legislation without broad appeal difficult to pass was a specific purpose of Congress’s design. The President, by comparison, is only one man, who at any given time may have multiple quacks and rent-seekers whispering sweet, economically illiterate nothings in his ear. What matters here is not whether Donald Trump is more or less virtuous than your average congressman, but that should he go into the business of picking winners and losers, there will be no one to check his worst impulses.
In addition to being vulnerable to corruption, government by executive order has another shortcoming: it is arbitrary, and therefore unpredictable. Under Barack Obama’s administration, businesses and investors noted how the uncertain regulatory environment created by his authoritarian governing style made it difficult for them to commit resources for hiring and product innovation. It is difficult to plan for the future when one cannot be sure would interrupt established practices and alter the cost of doing business.