From the National Journal: Death of the Swing Seat

In 2305 last we we looked at parties in Congress and how slowly over time they have become the dominant institution there. Charlie Cook discusses one of the factors which helps them consolidate their control, the fact that through party allies in the state legislatures districts have been gerrymandered to the point to where each party is guaranteed to hold a number of districts because they have been drawn that way. This point then also illustrates some of what we said in 2306 about the role of state legislatures and the items that dominate their agenda.

Cook points out that at best 1/4 of the seats in Congress are "swing seats" meaning that they are competitive. The Democratic and Republican candidate might each be likely to win the position. I've heard lower estimates. He uses this fact to point out how difficult it will be for Democrats to win back control of the US House in the 2014 elections. Republican dominated state legislatures - elected into office in the Tea Party wave of 2010 - designed a significant enough number of seats to give Republican a potential lock on the chamber through 2020. This suggests that the elections immediately following the census are very consequential because those are the legislatures that redraw districts.

. . . notwithstanding all the Democrats in Obama districts and Republicans in Romney districts, the chamber has fewer swing districts altogether. Using The Cook Political Report’s Partisan Voting Index, which ascertains how the presidential voting patterns in each congressional district differ from the national average, we took a look at the 2004 and 2008 presidential-election results in congressional districts (the final PVI incorporating the 2012 results will be available in the next month or so), and compared them with previous years. In 1998, there were 164 swing districts, which we define as a district with a Democratic or Republican PVI of 5 points or less. The swing districts outnumbered the 148 solid “R” districts where Republicans had an edge of more than 5 points, and the 123 solid “D” districts where Democrats had an edge of more than 5 points.

The number of swing districts dropped from 164 in 1998 to 132 by 2000, to 111 in 2002, then to 108 for two elections (2004 and 2006). The 2008 and 2010 cycles both had 103 swing districts, and the total slipped to 99 in the 2012 cycle. Currently, 190 districts have a Republican PVI over 5 points, 28 seats short of a majority; 146 districts have a Democratic PVI over 5 points, 72 seats short of a majority.

At one point there were more swing districts than safe Republican or Democratic districts. Not anymore. Does this contribute to the dysfunction currently on display in Congress?