Why have Republican leaders abandoned their principles in support of an immoral and dangerous president?

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: collusioncomplicityconnivance. 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.