319 Divided We Quarrel LEGISLATIVE STUDIES QUARTERLY, XXXIV, 3, August 2009 319 DAVID C.W. PARKER Montana State University MATTHEW DULL Virginia Tech University Divided We Quarrel: The Politics of Congressional Investigations, 1947–2004 Are congressional committee investigations into alleged executive-branch wrongdoing more common during periods of divided government? We analyze original data tracking congressional committee investigations into alleged fraud, waste, and abuse by the executive branch between 1947 and 2004. Countering David Mayhew’s (1991) empirical finding, we show that divided government generates more and more- intensive congressional investigations, but this relationship is contingent on partisan and temporal factors. Our findings shed new light on the shifting dynamic between partisan institutional politics and congressional oversight. Even casual observers of American politics might have foreseen the avalanche of investigations into alleged government malfeasance initiated by the 110th Congress (2007–08). New Democratic majorities in the House and Senate promised to scrutinize the alleged failings of an administration saddled by scandal and growing public discontent. Democrats promised to “drain the swamp,” in the words of new House Speaker, Nancy Pelosi. By one count, the number of investigations initiated in the first six months of the 110th Congress (605) outstripped those in the first six months of the 109th Congress (393), a spike widely attributed to the return of divided government. 1 The link between partisan conflict and congressional committee investigations features prominently in the media and in the minds of many observers. Sustained periods of divided government during the second half of the twentieth century have, in some cases, given way to real pessimism about the role of parties in American governance. In Politics by Other Means (1990), Benjamin Ginsberg and Martin Shefter contend that politicians, unable to establish decisive victories electorally, have turned to other institutional arenas in the competition for power. Consequently,