The right to travel is a part of the "liberty" of which the citizen cannot be deprived without due process of law under the Fifth Amendment * * * Freedom of movement across frontiers in either direction, and inside frontiers as well, was a part of our heritage. Travel abroad, like travel within the country, may be necessary for a livelihood. It may be as close to the heart of the individual as the choice of what he eats, or wears, or reads. Freedom of movement is basic in our scheme of values.285

The Kent opinion also suggested that grounds relating to citizenship and allegiance to illegal conduct might be the only two upon which the Department could validly deny a passport application.

The Department, though publicly declaring that these decisions had little effect upon its broadly worded regulation,286 in practice denied passports only in limited situations. In 1963 the Department denied passports only to those who violated the Department's travel restrictions, to fugitives from justice, to those involved in using passports fraudulently, and to those engaged in illegal activity abroad or in conduct directly affecting our relations with a particular coun-