In Ambach v. Norwick, 441 U. S. 68 (1979), the Supreme Court held that a State may bar aliens who have not declared their intent to become citizens from teaching in the public schools because teachers, like police, possess a high degree of responsibility and discretion in the fulfillment of a basic governmental obligation. They have direct, day-to-day contact with students, exercise unsupervised discretion over them, act as role models, and influence their students about the government and the political process. Id., at 78-79.