One of Harvey Mansfield’s signature contributions to understanding modern politics is to suggest the most basic distinction between the two parties can be reduced to opportunity (Republicans) versus entitlement (Democrats). His thoughts on the expansiveness—and therefore the threat—of the concept of entitlement are worth taking in from an essay published in 1984:
In the narrow sense an entitlement is a budget item that cannot be touched because the law awards it without reference to the number who claim it or to the cost. But the term has escaped into political philosophy and settled into American political practice. This challenges the distinction, essential to liberal constitutionalism, between the rights the government exists to protect and the exercise of those rights by private individuals, or between state and society. For an entitlement is a right whose exercise is guaranteed to a certain degree by the government—a right that is therefore exercised to that degree by the government. An equal right to seek a job, for example, becomes an entitlement to a job or rather to the proceeds of a job, which the government performs as it were instead of the worker. In this way government spreads into society, looking for more private activities to equalize and, with decreasing reluctance, to exercise itself instead of, yet on behalf of, those it wishes to benefit. Thus is grows unchecked by the liberal understanding that constitutional government must be limited in scope and methods, because the defenders of liberalism, the followers of Locke and Mill, have surrendered to the criticisms made by Marx and Nietzsche of the essential liberal distinction. The main obstacle to the growth of entitlements has been popular suspicion and opposition, applauded by a few conservatives, which have been more faithful to liberalism than have liberal intellectuals.