Final answer:
Jefferson's opposition to the Alien and Sedition Acts and support for the Kentucky and Virginia Resolutions are examples of actions that some believe violated the Constitution.
Step-by-step explanation:
Thomas Jefferson, one of the Founding Fathers of the United States, is often criticized for acts that some believe violated the Constitution. Two notable examples include his opposition to the Alien and Sedition Acts of 1798 and his support for the Kentucky and Virginia Resolutions. The Alien and Sedition Acts restricted free speech and press, which some Republicans saw as a violation of the First Amendment. The Kentucky and Virginia Resolutions asserted that states had the right to judge the constitutionality of federal laws and could declare them null if found unconstitutional.