That Americans disapprove of Congress is generally as well accepted as any stylized fact in American politics. From 1974 (when Gallup first asked a congressional approval question) through 1997, congressional approval hovered around 30 percent. The average for 54 Gallup polls taken over the 23 years was 31 percent. At no point did a majority of Americans approve of the way Congress did its job – approval climaxed in 1974 at 48 percent amid the Watergate proceedings. Such bleak numbers led Glenn Parker to conclude, “Congress, like Prometheus, is inevitably doomed to suffer indignities.” Sometimes, however, stylized facts turn out to be fiction. In 1998, Congress enjoyed widespread popular support, reaching a high of 63 percent in late September. Notwithstanding Congress' current popularity, the causes and consequences of the American public's disapproval of Congress have been studied in classrooms.

The myriad opinions and explanations of low congressional approval can generally be broken down into two schools of thought. The first argues that the American public's disapproval of Congress is based on policy or conditions. Low congressional approval is an artifact of either a recessing economy or policies inconsistent with the public's preferences.

On July 18, 2003, Chairman Bill Thomas substituted a bipartisan pension overhaul bill with a Republican-concocted plan less than 12 hours before the Ways and Means Committee mark-up. The Democrats, an already frustrated minority, vigorously retaliated. To stall committee action, all but one of the Democrats on the committee barricaded themselves in the committee library. Although Thomas called for the Capitol Police and the Sergeant at Arms to evict the Democrats, neither chose to get involved in the highly charged partisan fight. Representative Pete Stark, the only committee Democrat not in the library, continuously objected to Thomas's unanimous consent to dispense with the bill's reading. On one particular attempt, Thomas banged down the gavel before Stark could object. When Stark criticized Thomas's move, Representative Scott McInnis told him to “shut up.” Stark retorted, “You think you are big enough to make me, you little wimp? Come on, come over here and make me, I dare you…You little fruitcake. You little fruitcake. I said you are a fruitcake.” Overtly partisan games quickly deteriorated into playground taunts. After Democrats and the political pundits used the weekend political shows to ridicule him, Thomas offered a tearful apology on the House floor for his heavy-handed tactics.

Although a news story for less than a week, this event has come to typify the relationship between Democrats and Republicans on Capitol Hill. The majority party has a substantive goal (business-friendly reforms for the pension system).

Upon his return to the United States, Thomas Jefferson, who missed the constitutional convention because he was in Paris serving as an ambassador, queried George Washington about why he ever accepted the aristocratic characteristics of the U.S. Senate. Washington was to have famously remarked: “We pour legislation into the senatorial saucer to cool it.” The framers, wary to draw too direct a line between the impulse of the people and public policy, created a complex lawmaking system to dampen the people's demands. Chief among these was the Senate. As Madison explains in Federalist 63, “Such an institution [as the Senate] may be sometimes necessary as a defense to the people against their own temporary errors and delusions.” Only the persistent and enduring demands from the people would enjoy a hearing and successful disposition in the Senate. By virtue of its design and practice over the past 220 years, the Senate has been less likely to be captured by the trends of the day than the House. As I show repeatedly throughout this book, however, even the Senate's tradition of comity and supermajoritarian requirements have not been able to preclude party polarization from pervading it.

Since the early 1970s, the Senate has polarized about 80 percent as much as the House. That the Senate has polarized almost as much as the House is surprising given that at both the electoral and the institutional levels, the House is more easily manipulated than the Senate.

Part III of this book investigates institutional change in Congress, which is an intermediate step between constituency change (as analyzed in part II) and party polarization (as described in part 1). Although the changes taking place in members' constituencies have had a statistically significant and noticeable effect on party polarization, it alone does not explain all or even a majority of it. In part III of the book, I find that the lion's share of party polarization has come about as a consequence of the procedural divide between Democrats and Republicans in both the House and the Senate. To be sure, this procedural divide has roots in the growing partisanship of members' constituencies. These changes must interact with the legislative process for a clearer picture of party polarization to come into focus.

Chapter 7 examines the effect that increasing partisanship of members' constituencies has on the internal dynamics between members and their party leadership (arrow E in figure 3.2). As the party caucuses' constituencies have become more internally homogeneous, the rank and file members have been more willing to cede to their party leadership an increasing scope and use of powers so that they can entice, cajole, compel, or force party loyalty among the rank and file members. More polarized caucuses have led to more polarized party and committee leaderships in both chambers of Congress.

Michigan's Livingston County is strategically situated. It is less than an hour's drive from both the state capitol in Lansing and the auto manufacturing international headquarters in Detroit. Even as the industry in Michigan has shed high-paying low-skilled jobs, Livingston County's population has experienced growth almost unrivaled in the state, increasing more than 166 percent over the past 30 years. In contrast, Wayne County, where much of Detroit is located, has lost almost 23 percent of its population over the same time period.

Livingston and Wayne are not only experiencing divergent population changes, but also as the residents politically sort themselves, move in, and leave the area, the demographics of these counties have similarly diverged. Wayne was 27.7 percent African American in the 1970s. In the 2000 census, that percentage increased almost 15 percentage points to 42.2 percent. Although the median household income in Wayne County has tripled over the 30 years, its residents went from earning about 1 percent more than Michigan's median to earning nearly 9 percent less. Although Livingston's black population has not changed much (in the 2000 census, it was still less than one-half of 1 percent), the residents' increase in earnings has nearly doubled those in Wayne. Whereas Livingston's median household earned almost 9 percent more than Michigan's median in 1970, it now earns more than 50 percent more than the state's median.

Part I of this book provides the base from which my polarization argument builds in parts II and III. Chapter 2 lays out a systematic description of party polarization and how it has varied over time. The twentieth century began with parties that were even more polarized than the parties today, but the ideological gap between them narrowed for much of the twentieth century. Beginning in the early 1970s, however, members of both parties in both chambers began casting more divisive votes. Chapter 3 places the existing explanations for this increased polarization over the past three decades into a comprehensive model that is then rigorously analyzed in the remainder of the book.

One year to the date after the Supreme Court's Bush v. Gore decision brought the 2000 presidential election to an end, the House of Representatives passed the Help America Vote Act (HAVA). By passing the bill, which authorized $2.65 billion to help localities both update antiquated voting equipment and recruit, hire, and train poll workers, House members hoped they had solved the problems that led to the fiasco in Florida. Three hundred and sixty-two legislators, which included substantial majorities of both parties, voted for the bill's final passage; only 20 Republicans and 43 Democrats voted against it.

Congressional observers and the American public may have been surprised to see the House, an institution criticized for being trapped in partisan warfare, find a bipartisan solution to one of the most highly partisan episodes in American history. Indeed, Democrats and Republicans alike praised House Administration Committee Chair Bob Ney and Ranking Member Steny Hoyer for working together to insure that future ballots are properly cast and appropriately counted. Congressman Chaka Fattah, a Democrat on the committee, offered the following assessment during floor debate: “I want to thank Chairman Ney, who I think has exhibited extraordinary leadership in moving this forward, and Ranking Member Hoyer, [for] bringing together a bipartisan group of people.”

Georgia gained one seat in the 1990 round of reapportionment. In creating the new district and altering the old districts to achieve population-equal congressional districts, the Democratic state legislature and Democratic governor pursued multiple objectives: protect the Democratic incumbents in the House, maximize the number of Democratic districts, to divide up the constituency of its lone Republican congressman (Newt Gingrich), and gain the Department of Justice's assent as mandated by the preclearance provision in the Voting Rights Act of 1965. Although the state legislature passed and the governor signed various plans, the Department of Justice, under a directive from President George H.W. Bush, rejected them because they failed to maximize minority representation. Eventually the state legislature relented and created a third black district in the Atlanta suburbs.

The “bleaching” of the districts surrounding the black majority districts and a Republican wave in the wake of Clinton's first two years in the White House radically changed the state's congressional delegation. In the 102nd Congress, the last one using the 1980 district lines, Georgia voters sent one liberal African American Democrat, six moderate Democrats, two conservative Democrats, and one even more conservative Republican to the House. In the 107th Congress, the last election using the 1990 census data, Georgia sent two liberal African American Democrats, one moderate African American Democrat, and eight more or less conservative white Republicans to Congress (see panel A of figure 4.1). The Democratic legislature and governor's best-laid plans went seriously awry.