executive one. When he presided over the Senate, emotions sometimes ran high. During a debate on the Mexican border crisis in 1916, Marshall threatened to expel certain senators from the chamber for their raucous behavior, but did not carry through on the threat. On several occasions, he ordered the Senate gallery cleared. He voted eight times to break tie votes. In the debates leading up to World War I, a number of isolationist senators filibustered bills that Wilson considered important. The filibusters lasted for weeks and twice lasted for over three months. Wilson and the bills' supporters requested that Marshall put a gag-order in place to cut off debate, but he refused on ethical grounds, allowing a number of bills to be defeated in hopes that opposition would eventually end their filibuster. Among the defeated bills was one allowing merchant ships to arm themselves, and another allowing the US government to make direct arms sales to the Allies. Despite their victories, the small group of senators continued to lock up the senate to prevent any pro-war legislation from passing. In response, Marshall led the Senate to adopt a new rule on March 8, 1917, allowing filibusters to be broken by two-thirds of voting Senators. This replaced the previous rule that allowed any senator to prolong debate as long as he desired. The rule has been modified several times, most prominently that the current rule requires three-fifths of all Senators, not only the ones voting. As Marshall made little news and was viewed as a somewhat comic figure in Washington because of his sense of humor, a number of Democratic party leaders wanted him removed from the 1916 reelection ticket. Wilson, after deliberating, decided keeping Marshall on would demonstrate party unity; thus in 1916 Marshall won reelection over the still divided Republican Party and became the first vice president re-elected since John C. Calhoun in 1828, and Wilson and Marshall became the first president and vice president team to be re-elected since Monroe and Tompkins in 1820. Assassination attempt On the evening of July 2, 1915, Eric Muenter, a one time German professor at Harvard and Cornell universities, who opposed American support of the Allied war effort, broke into the U.S. Senate and, finding the door to the Senate chamber locked, laid dynamite outside the reception room, which happened to be next to Marshall's office door. Although the bomb was set