In politics, gridlock refers to the difficulty of passing laws fulfilling a party's political agenda in a legislature that is nearly evenly divided, or in which two legislative houses, or the executive branch and the legislature are controlled by different political parties. In the United States politics, gridlock frequently refers to occasions when the United States House of Representatives and the United States Senate are controlled by different parties, or by a different party than the party of the president. Gridlock may also occur within the Senate, when no party has a filibuster-proof majority.
Law professors such as Sanford Levinson and Adrian Vermeule, as well as political commentators such as Matthew Yglesias, have criticized the U.S. Constitution and Senate voting rules for contributing to legislative gridlock.
See also: United States presidents and control of congress