I think that both thinkers played a formative role in the creation of the Constitution and help to create the vibrant political debate that surrounds modern political experiments. The framers of the U.S. Constitution knew of both thinkers quite well. Locke was an Enlightenment thinker present in the emerging stages of the new nation, playing a vital role in Jefferson's "Declaration of Independence." The concept of inalienable rights and the notion of "life, liberty, and the pursuit of happiness" was a Lockian idea, with the slight alteration from "pursuit of property." In the creation of the Constitution, the ideas that Locke espoused in his philosophy were present, as well. The notion of specific rights that citizens are to enjoy without intrusion from an external force are present in the Bill of Rights. The principle of popular sovereignty derives from Locke's idea that government is an arrangement between the governed and those in the position of political power. Any violation of that agreement can, and should, result in a change of leadership. This idea was embedded in the framers' vision of government and owes much of its existence to Locke.
Hobbes' premise of how political leadership must subsume the rights of the individuals for fear of chaos and a brutal state of nature was present in the framers' mind, as well. The framers could not very well embrace Hobbes' Leviathan autocratic figure as this would go against the constitutional democratic order they desired. Instead, they understood that Hobbesian state of nature, where human beings are constantly at war with one another, could only be fully addressed in the construction of a legal system that created spheres of existence where individuals could pursue their own interest but possessed the fundamental right to be left alone and to ensure that a proximal zone of freedom prevented encroachment from another. This idea would go very far to preventing Hobbes' view of human nature where humans are constantly at war with one another.
To a great extent, both thinkers are present today in that democratic orders are completely driven by discussions of political authority and the rights of their citizens.