Marshall presided over the impeachment trial of Vice President Aaron Burr in 1807 in his capacity as a circuit judge. Marshall’s rulings in the case effectively nullified the prosecution’s treason charges against Burr. His rulings also increased the antagonism of President Thomas Jefferson, a Democratic-Republican, who was not an ally of Marshall, a Federalist. The two had clashed through the years and the Marbury case only served to exacerbate tensions between the two political rivals.