President Trump’s declaration of a national emergency to seek funds for building a wall on the southern U.S. border relies for its authority on the 1976 National Emergencies Act, which gives presidents sweeping powers to address what they declare are urgent crises. But for a historian of modern Germany, it’s impossible to avoid recalling the way emergency declarations unsettled the Weimar Republic after World War I.

The Weimar constitution, like ours, had classically liberal aspects that guaranteed freedom of speech, assembly, religion and the right to private property. Yet born in the context of near-civil war conditions between right and left, it also gave the nationally elected president the power to dissolve the parliament and hold a new election within 60 days. Its Article 48 gave the president the power, “if public security and order” were “seriously disturbed or endangered within the German Reich,” to use the armed forces to restore them or suspend “for a while in whole or in part fundamental rights” guaranteed by the Constitution such as freedom of assembly and speech.

In his 2014 study, “Rethinking the Weimar Republic: Authority and Authoritarianism, 1916-1936,” the historian Anthony McElligott writes that in the crisis years after the beginnings of the Great Depression in 1929, the idea of “dictatorship within the bounds of the constitution” played a central role in “shifting the republic from democratic authority toward authoritarian democracy,” aided by those who sought a “strong leader” as an antidote to the apparent failure of party politics.