For the general election, McCormick was up against Democratic nominee former Senator James Hamilton Lewis. Lewis previously lost the seat to Medill in 1918. William Thompson, who had supported McCormick in the primary, threw his support to Lewis in the general election. One contentious issue in the campaign was Prohibition, which McCormick supported and Lewis did not. However, some Prohibitionists thought that McCormick was insufficiently committed to prohibition, and several defected to the "Independent Republican" campaign of Lottie Holman O'Neill. The high cost of McCormick's primary campaign also became a point for attack in the general election, with Lewis accusing McCormick of trying to buy the election. Lewis also made a point not to refer to McCormick by name, instead calling her "the lady candidate". McCormick refused to make her gender an issue, calling gender differences a personality issue and insisting political party mattered more in the general election. Unfortunately for McCormick, 1930 was a difficult year for Republican candidates as the stock market crash had occurred the year before. McCormick lost the election, 64% to 31%. Her term in office as a Congresswoman came to an end on March 3, 1931.