參考文獻
George C. Edwards, Martin P. Wattenberg, and Robert L. Lineberry, Government in America: People, Politics, and Policy (New York: Pearson, 2009), 388-89
Douglas Barclay, “Democrats and Republicans Far Apart on Issues Ahead of Thanksgiving”(26 November 2019), www.prri.org/spotlight/democrats-and-republicans-far-apart-on-issues-ahead-of-thanksgiving/
“Political Polarization in the United States”, www.facinghistory.org/sites/default/files/Explainer_Political_Polarization.pdf
〈「驢象兩黨」國會對峙美眾議院通過彈劾調查程序〉（2019年11月2日），新華網，www.xinhuanet.com/world/2019-11/02/c_1210337200.htm
“2018 Midterm Elections”, www.nbcnews.com/politics/2018-election/midterms