During the Adams presidency, the Federalists rebuilt the military, levied new taxes, and enacted the Alien and Sedition Acts. Jefferson believed that these laws were intended to suppress Democratic-Republicans, rather than prosecute enemy aliens, and considered them unconstitutional. To rally opposition, he and James Madison anonymously wrote the Kentucky and Virginia Resolutions, declaring that the federal government had no right to exercise powers not specifically delegated to it by the states. The resolutions followed the "interposition" approach of Madison, in which states may shield their citizens from federal laws that they deem unconstitutional. Jefferson advocated nullification, allowing states to invalidate federal laws altogether. Jefferson warned that, "unless arrested at the threshold", the Alien and Sedition Acts would "necessarily drive these states into revolution and blood".