Anne Applebaum in The Atlantic:
In english, the word collaborator has a double meaning. A colleague can be described as a collaborator in a neutral or positive sense. But the other definition of collaborator, relevant here, is different: someone who works with the enemy, with the occupying power, with the dictatorial regime. In this negative sense, collaborator is closely related to another set of words: collusion, complicity, connivance. This negative meaning gained currency during the Second World War, when it was widely used to describe Europeans who cooperated with Nazi occupiers. At base, the ugly meaning of collaborator carries an implication of treason: betrayal of one’s nation, of one’s ideology, of one’s morality, of one’s values.
…To the american reader, references to Vichy France, East Germany, fascists, and Communists may seem over-the-top, even ludicrous. But dig a little deeper, and the analogy makes sense. The point is not to compare Trump to Hitler or Stalin; the point is to compare the experiences of high-ranking members of the American Republican Party, especially those who work most closely with the White House, to the experiences of Frenchmen in 1940, or of East Germans in 1945, or of Czesław Miłosz in 1947. These are experiences of people who are forced to accept an alien ideology or a set of values that are in sharp conflict with their own. Not even Trump’s supporters can contest this analogy, because the imposition of an alien ideology is precisely what he was calling for all along. Trump’s first statement as president, his inaugural address, was an unprecedented assault on American democracy and American values. Remember: He described America’s capital city, America’s government, America’s congressmen and senators—all democratically elected and chosen by Americans, according to America’s 227-year-old Constitution—as an “establishment” that had profited at the expense of “the people.” “Their victories have not been your victories,” he said. “Their triumphs have not been your triumphs.” Trump was stating, as clearly as he possibly could, that a new set of values was now replacing the old, though of course the nature of those new values was not yet clear.