President Trump injected more uncertainty into the US economy by tweeting late Monday night his intent to sign an Executive Order temporarily suspending legal immigration to the United States. The terms, reasoning, and legal authority for the Executive Order are unclear, as it has not yet been released, and his announcement appears to have caught DHS officials by surprise.

In a press conference on Tuesday, President Trump stated that his plan would not affect temporary workers but would be in effect for 60 days and could be extended after 60 days “based on economic conditions at that time.” According to media reports, some officials have suggested that the Order would exempt essential workers and the spouses and children of US citizens. Regardless of its terms, the Executive Order will almost certainly be challenged in court.

This proposed order has been heavily criticized on both the left and the right for its xenophobia, irrationality, and ineffectiveness. However, my concern about President Trump’s proposed Executive Order is more fundamental: its lack of democratic legitimacy.

Under our Constitutional system, it is Congress that writes the law — not the President. The President can decide on which areas of law enforcement to focus limited resources, and in so doing, can decide that enforcing the immigration laws against certain categories of people is not justified on policy grounds. But the converse is not true: he cannot usually restrict rights or create new grounds for enforcement on his own.

While it is true that the Supreme Court held in Trump v. Hawaii (2018) that the Executive wields a good deal of discretion when it comes to immigration enforcement, this principle emerged in a case in which questions of national security were deemed to be at stake and in which the restrictions proposed affected a much smaller number of people, given both the scope of the ban and various waiver provisions. (This is not to suggest that the third version of the “Muslim ban,” which was upheld by the Supreme Court is not devastating — just that it should not serve as a precedent). The President’s decision-making authority is at its highest when questions of foreign relations and national security are at stake, not when discussing labor market conditions. Here, Trump has not appeared to ground his proposal not on public health or national security grounds, but on protecting American workers. (He did mention in his press conference Tuesday that pausing legal immigration would preserve healthcare resources for Americans, but this justification appeared to be secondary to labor market concerns).

Whereas the economic impact of Covid-19 on the US likely constitutes an “emergency” in terms of its gravity, it is not such an emergency — in terms of timeliness — that Congress should abdicate its law-making responsibilities. To the contrary: it is precisely when the nation faces a crisis that we should most vehemently insist that tough decisions be made by a representative body rather than a single person. Congress has passed a stimulus plan and is working on another. This legislation can be criticized on its merits, but at least it was not done by fiat; the legislation was important, and Congress found the time.

Immigration policy involves complex empirical questions and difficult trade-offs. Different regions of the country and segments of the economy often have different priorities. Immigration debates bring into sharp focus our nation’s identity and values. How strongly do we value families? Providing refuge for those fleeing persecution? Economic growth? Fundamental fairness? If foreign workers do, in fact, have an impact on the job prospects for American workers, in what direction is this impact, how large is it, in which industries, in which regions, and how are these answers likely to change over time? During a pandemic, do we, in fact, have enough healthcare resources to receive new immigrants, given both the cost and the benefits of immigration, including the immigration of high-skilled medical workers? These are not purely “technical” or “administrative” questions that should be delegated to the enforcement experts at DHS or DOL or HHS: these are huge policy questions that go to the heart of democratic decision-making, especially in times of a crisis.

It is the job of Congress to figure out the best policy and political solutions by consulting experts, holding public hearings, opening themselves up to media scrutiny, listening to constituents, and hammering out compromises. If immediate action is needed because the country is in full crisis mode during a pandemic, then the Executive can temporarily suspend travel into the country (when not inconsistent with international law): a longer-lasting and broader suspension of rights is not necessary. This is not a situation in which the President is claiming emergency authority to temporarily close the border in the early stages of a pandemic, before the US led the world in the number of infections and deaths (though not per capita).

Congress is free to create new immigration restrictions based on the desire to protect American workers or to preserve healthcare resources for current residents, so long as these restrictions do not violate the US Constitution or interfere with our commitments under international law to protect refugees. However, if Congress does so, individual legislators must take the political heat, by defending those arguments to American voters in the districts and states they represent. Not surprisingly, these arguments do not sit well with large swaths of American voters, many of whom were once immigrants themselves and even more whose spouses, parents, colleagues, friends, employees and students are immigrants. Universities and businesses often strenuously lobby against such restrictions, on the theory that historically the key to the US’s success — especially in times of crisis — has been its relative openness to immigration.

Indeed, the representative structure of our law-making — the fact that a bill must pass both the House and the Senate, and then survive a Presidential veto — places a check on our most extreme tendencies. In all its messiness, horse-trading and tedium, the politics of the legislative process — the committees, hearings, drafts, debates, media scrutiny, town halls, constituent calls, public protests — is what gives our laws legitimacy and what helps creates laws that, if not necessarily good, are at least usually not terrible.

Moreover, the very difficulty of changing the law, due to the messiness and political negotiations involved in democratic decision-making, is part of what distinguishes the US from authoritarian regimes like Russia or China. The US tends to put a high value on protecting reliance interests and still leads the world in innovation, in large part because it can attract the world’s best students and researchers, particularly in science, medicine, technology and engineering (with the exception of students from certain countries from which the US makes legal immigration almost impossible).

If our government puts businesses and would-be immigrants on notice that we are unpredictable and unreliable — that the value of their plans and investments can be destroyed or delayed indefinitely by the stroke of one man’s pen — then it invites the risk that many of them will decide to immigrate to Canada, Europe, or other countries and regions with more predictable governments. Highly-skilled immigrants continue to put up with the difficulty of our immigration system because the corresponding benefits of immigration to the US are so great. But we should take the desirability of the US for granted. If we are too mercurial — too unwelcoming, unpredictable, arbitrary, inefficient, unprofessional — people will go elsewhere.