What if we told you that the gerrymandering of congressional districts has nothing to do with political polarization in Washington? Gerrymandering didn't have anything to do with the shutdown, or the battles over the debt ceiling or Obamacare. In fact, the accepted view that politically based redistricting led to our state of intransigence isn't just incorrect; it's silly.
The real reason for our increasingly divided political system is much simpler: The right wing of the Republican Party has embraced a fundamentalist version of free-market capitalism and succeeded in winning elections. (The Democrats have moved to the left, but less so.)
The Republican shift is the result of several factors. The realignment of Southern white voters into the Republican Party, the branch of conservative activism created by Barry Goldwater's 1964 presidential campaign and the party's increasingly firm stance on issues such as income inequality and immigration, can all be important to Republicans' rightward shift.
The "blame it on the gerrymanders" argument mistakenly assumes that because redistricting created more comfortable seats for each party, polarization became inevitable. Our research casts serious doubt on that idea.
The most important element affecting polarization in the House of Representatives is the divergent approaches that Democrats and Republicans take to representing districts that are otherwise similar in terms of demographics and presidential voting. Even in moderate districts, Democratic representatives are still very liberal and Republican representatives are very conservative. This reflects a widening ideological gap, not different lines on a map.
Consider, for example, the rise of the mastermind of the shutdown, Sen. Ted Cruz. The Texas Republican won his seat, as does every member of the Senate, in a statewide race, without any benefit from gerrymandering. The same is true for other Tea Party stalwarts in the Senate such as Rand Paul of Kentucky and Mike Lee of Utah.
The analysts who are wedded to the view that gerrymandering is at the root of the congressional impasse argue that rancor spread to the Senate from the House. Yet it could also be argued that the force-feeding has run in the other direction, that it was Mr. Cruz who stimulated adamancy among Tea Party conservatives in the House, leading to the standoff on the budget and debt ceiling.
As for the shifting ideology of the House, political scientists have demonstrated that whenever a congressional seat switches parties, the voting record of the new member is very different from that of the departing member, increasing polarization. In other words, it is becoming more common to observe a very liberal Democrat replaced by a very conservative Republican (and vice versa).
Such a shift happened in Minnesota. In 2010, one of the liberal giants in the House, Jim Oberstar, was defeated by former Navy pilot Chip Cravaack. As a congressman, Mr. Cravaack compiled a reliably conservative voting record and even supported Michele Bachmann's bid for a House leadership position. But in 2012, Mr. Cravaack was defeated by Rick Nolan, a liberal Democrat. So in the course of four years, Minnesota's 8th District swung from liberal to conservative back to liberal. Gerrymandering can't explain this pattern of turnover.
The number of politically safe seats in the House isn't fully explained by gerrymandering, either. Other, longer-term trends play a role, too.
The regional realignments that gave Democrats control of the Northeast and Republicans control of the South in the 1960s and 1970s have had a large impact on the ideological makeup of Congress, as have the increasing interest gaps between urban and rural voters.
There is another distinction. Many districts are safe for one party or the other because of how Americans have sorted themselves geographically, choosing to live closer to people who are politically or culturally like-minded. In Florida, for example, Palm Beach County will be reliably Democratic and the Panhandle will consistently vote for Republicans. These geographic shifts mean that state legislatures, which approve congressional district lines, can tweak but not fundamentally alter the ideological makeup of Congress.
Congress also has a handful of representatives from one-district states such as Vermont and Wyoming that can't be subject to gerrymandering. Yet they are just as partisan as their colleagues from gerrymandered districts in other states.
The gerrymandering myth doesn't do a good job of accounting for recent political history, either. After the reapportionment based on the 2000 census, Republicans maintained control of the House in 2002 and 2004. But Democrats won control of the House in 2006 and extended their margin in 2008. Republicans won back the majority in 2010. (Reapportionment after the 2010 census only took effect in 2012.)
So the 2000 reapportionment not only failed to give Republicans firm control of the House, it also gave Democrats opportunity to pass a series of bills that Republicans continue to battle, including the Affordable Care Act, the Dodd-Frank financial regulations, the stimulus package and credit-card reform.
Ideologies are rigid and evolve slowly. Political polarization can be attributed to a number of factors, but evidence shows gerrymandering isn't one of them.opinion_commentary
Nolan McCarty is the Susan Dod Brown Professor of Politics and Public Affairs at Princeton University. Keith T. Poole is the Philip H. Alston Jr. Distinguished Professor at the University of Georgia. Howard Rosenthal is a professor of politics at New York University. They wrote this for Bloomberg News. First Published October 10, 2013 8:00 PM