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  • Matthew Green

Political parties in Congress: a ten-year retrospective

Since the Mischiefs of Faction blog started ten years ago, the platforms, leadership, and strategies of political parties in Congress have changed in many important ways. A few changes in particular are worth noting – not only for their impact on how Congress functions, but also as a reminder that our four congressional parties (House and Senate Democrats, House and Senate Republicans) do not always follow the same developmental path.

1. Greater diversity. Congressional parties have become more diverse over the past decade. Both parties in both chambers have more women members than ever before. A growing number of lawmakers are non-Christian or do not identify with a particular denomination.

This diversity is not distributed equally between the parties; far more Republicans than Democrats are Christian men, for example. But overall, such increase in descriptive representation brings Congress closer to being an “exact portrait of the people at large,” the ideal touted by John Adams. Political science research has also shown that diversity in Congress has an impact on everything from voting to constituent advocacy.

2. More polarized voting. Perhaps the most widely noted trend in congressional party politics over the past decade is an increase in voting polarization. For instance, the average party unity score of lawmakers -- measured as the average frequency with which a lawmaker casts their ballot with their party on a vote which pits a majority of one party against a majority of the other – have increased to near-record highs.

But not every party has polarized equally. As has long been the case, members of the minority show less unity, in part because the governing party can use its agenda control to bring up measures that divide the minority. And in the Senate, where such agenda control is weaker, one sees less polarization. It is a reminder that voting behavior is driven not only by policy differences but also by institutional differences.

3. More internal divisions. Paradoxically, this increased voting unity since 2012 belied another, arguably more important development: the rise of assertive party factions willing to hold their own party’s agenda hostage to get their way. The most obvious example has been the House Freedom Caucus, which was created in 2015 and became a major player in both the House and in the Trump presidency. In the current Congress, House Democrats struggled at times with the Progressive Caucus, a much larger group that has used its size to try forcing changes to the party’s agenda.

Such factions are less important in the Senate. As Ruth Bloch Rubin has observed, the chamber is less friendly territory for intraparty organizations. But individual senators can cause problems for their party, and the extremely narrow margin in the Senate over the past two years has given lawmakers like Sen. Joe Manchin (D-WV) outsized influence.

4. Stability in leadership. A final striking development over the past decade is the lack of turnover in congressional party leadership. Nancy Pelosi remains the House Democrats’ top leader and Steny Hoyer is their number two (and have held those positions for nearly two decades.) In the Senate, Mitch McConnell is still the leader of Republicans, and while Democrats have a new leader (Chuck Schumer, who replaced Harry Reid in 2017), Dick Durbin has been Democratic Whip since 2005.

This lack of leadership change has been criticized for, among other things, driving out ambitious young lawmakers who have no way to climb the leadership ladder. But it can also be credited for ensuring the parties have had experienced leaders at the helm during difficult times (like the Trump presidency).

The important exception to this trend is House Republicans, who have been through two Speakers (John Boehner and Paul Ryan), two minority/majority leaders (Eric Cantor and Kevin McCarthy), and two whips (McCarthy and Steve Scalise). This is partly a consequence of the party’s internal divisions, which have made governing difficult. And should Republicans win control of the House in November, the lack of an experienced leader at the party’s helm could come back to haunt them.

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