Final answer:
The Democratic-Republicans, including Thomas Jefferson and James Madison, contested that the Alien and Sedition Acts violated First Amendment freedoms and used the Virginia and Kentucky Resolutions to challenge these federal encroachments on civil liberties and state sovereignty.
Step-by-step explanation:
The Alien and Sedition Acts of 1798 led to significant debate around the First Amendment rights—particularly regarding freedom of speech and press—and the balance of power between the federal and state governments. The Democratic-Republicans, led by Thomas Jefferson and James Madison, contended these acts violated constitutional protections and individual liberties by expanding federal powers excessively. Jefferson and Madison's Virginia and Kentucky Resolutions introduced the controversial concept of nullification, suggesting that states had the authority to nullify federal laws deemed unconstitutional. However, many other states did not rally to this perspective, emphasizing the need for national cohesion and security, especially given the international context of the Quasi-War with France.
While the Sedition Act specifically aimed at regulating speech against the government, this perceived infringement on the First Amendment was met with strong opposition from Republicans. They believed these acts were a reactionary measure from the Federalists designed to suppress dissent and weaken the opposition party rather than a necessary protective measure amidst international concerns. Ultimately, these acts and their subsequent opposition had a considerable impact on the political landscape and played a part in the eventual end of the Federalist era with Jefferson’s election in 1800.