Month: March 2015

Congressional Policy Shifts, 1879-2014

voteviewblog 113th Congress, 114th Congress, Political Polarization

Below we use first dimension DW-NOMINATE scores, which represent legislators’ positions along the familiar ideological (liberal-conservative) spectrum, with lower (negative) scores indicating greater liberalism, and higher (positive) scores denoting conservatism, to plot the chamber means for legislators and winning outcomes on roll calls for Congresses 46 to 113 (2014). These are updates to Figure 4.1 (page 60) in Poole and Rosenthal’s Congress: A Political-Economic History of Roll Call Voting and Figure 4.1 (page 80) of Ideology and Congress.

We see that the overall chamber means (plotted with red squares) remain mostly stable over time, a reflection of a competitive two-party system. Of the two chambers, the House mean has shifted more to the right in the period following the 104th Congress (the 1994 “Republican Revolution”). However, the position of the mean winning coordinate in each chamber has proved much more volatile, particularly in recent Congresses. This reflects the frequency of party-line votes between rival partisan coalitions that have moved steadily apart in recent decades.

Consequently, the mean winning coordinate–-which is an approximation of the ideological location of policies enacted in the chamber–-has diverged from the overall mean chamber score in both chambers: to the left under Democratic control, to the right under Republican control. Indeed, the mean winning coordinate in the 111th Senate (a session in which the number of Senate Democrats fluctuated between 57 and a supermajority of 60) was the furthest to the left since the 75th Senate during the Great Depression and the New Deal. Further, the mean winning coordinate in the 113th House was the most conservative since the late nineteenth and early twentieth centuries, following the realigning election of 1896, after which Republicans controlled the House for 32 of the next 38 years. Conversely, the mean winning coordinate in the 113th Senate was the most liberal since the late nineteenth century.

Click images to enlarge



House: Vote on Clean DHS Funding Bill

voteviewblog 114th Congress

Below we use updated DW-NOMINATE scores to plot the House’s 257-167 vote to pass a clean funding bill for the Department of Homeland Security (DHS).

The cutting line (separating predicted Yea votes from predicted Nay votes) divides the 75 Yea Republicans from the 167 Nay Republicans along both the first dimension (representing liberal-conservative position) and the second dimension. The meaning of the second dimension has largely shifted from representing regional differences within the parties (e.g., between northern and southern Democrats) to intra-party divisions that are more subtle and less clear. One of these divisions appears to be an “insider vs. outsider” cleavage that pops up on votes such as raising the debt ceiling, domestic surveillance, and government funding bills.

This image is from a new stand-alone DW-NOMINATE that can be run daily as new roll calls are cast. We will have more to say about this software at a later date.

Click image to enlarge


Note: The plot shows only 256 Yea votes because Speaker John Boehner (R-OH) voted Yea but has not cast enough votes (25) to be included in the scaling.

Senate: Vote to Override Keystone XL Pipeline Veto

voteviewblog 114th Congress

Below we use updated DW-NOMINATE scores to plot the Senate’s 62-37 vote to override President Obama’s veto of a bill approving construction of the Keystone XL pipeline. The Senate fell five votes short of a successful veto override.

Eight Senate Democrats joined all 54 Senate Republicans in supporting the override. These eight Democrats are among the most moderate members of their party’s caucus, and DW-NOMINATE accounts for this in projecting the cutting line as running through the right edge of the Senate Democrats.

It is also worth noting the degree of ideological dispersion among Republicans in the 114th Senate, which runs the gamut between moderates like Senators Mark Kirk (R-IL) and Lisa Murkowski (R-AK) and strong conservatives like Senators Ted Cruz (R-TX) and Rand Paul (R-KY), with a first dimension (ideological) distance of approximately 0.8 between these two clusters.

This image is from a new stand-alone DW-NOMINATE that can be run daily as new roll calls are cast. We will have more to say about this software at a later date.

Click image to enlarge


Note: The plot does not include Senate Minority Leader Harry Reid (D-NV), who voted Nay but has not yet cast enough votes to be included in the scaling.

House: Vote on Three-Week DHS Funding Bill

voteviewblog 114th Congress

Below we use updated DW-NOMINATE scores to plot the House’s 203-224 vote to reject a three-week funding bill for the Department of Homeland Security (DHS).

Ideology appears to do a good job of dividing the 191 Yea Republicans from the 52 Nay Republicans, with (predictably) those Republicans opposing the measure being more conservative than those supporting it. There is somewhat of a “two-ends-against-the-middle” pattern on this vote, with the 12 Democrats who voted Yea being more moderate than the remainder of their caucus.

This image is from a new stand-alone DW-NOMINATE that can be run daily as new roll calls are cast. We will have more to say about this software at a later date.

Click image to enlarge


Note: The plot shows only 202 Yea votes because Speaker John Boehner (R-OH) voted Yea but has not cast enough votes to be included in the scaling.