In Conversation

Polarization in U.S. politics starts with weak political parties

Ian Shapiro, Sterling Professor of Political Science at Yale, says weak political parties are responsible for the polarization in American politics.
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When Joe Biden assumes the presidency on Jan. 20, he will lead a deeply polarized nation facing historic challenges. As the COVID-19 pandemic continues to surge, with more than 11 million U.S. cases and 246,000 deaths, Americans and their elected leaders can’t even agree on basic measures to protect public health.

How did we become so divided? 

Ian Shapiro, Sterling Professor of Political Science, has examined the origins of political polarization. In his 2018 book, “Responsible Parties: Saving Democracy from Itself,” co-authored with Yale colleague Frances McCall Rosenbluth, Shapiro argues that the transfer of political power to the grassroots has eroded trust in politicians, parties, and democratic institutions, culminating in the rise of divisive, populist politics in the United States and abroad. 

Ian Shapiro
Ian Shapiro (Photo credit: Mara Lavitt)

Shapiro recently spoke to YaleNews about what’s ailing American politics. The interview has been edited and condensed. 

How have the last four years affected the country’s political institutions?

Many people are concerned about the damage Trump has inflicted on America’s political institutions. What they are missing is that Trump is a product of bad political institutions. The main infirmity is that the United States has very weak political parties. They are weak because they are subject to control by unrepresentative voters on their fringes and those who fund them.  

Why do voters on the fringes have such influence?

It’s due to the role of primaries at the presidential level and the interaction of primaries and safe seats in Congress. Primaries are not new; we’ve had them since the Progressive era. The basic problem with them today is they are usually marked by very low turnout and the people on the fringes of the parties vote disproportionately in them. The same is true of caucuses. Donald Trump was selected as the Republican presidential candidate in 2016 by less than 5% of the U.S. electorate. 

A similar dynamic plays out in Congress. The Tea Party’s takeover of the Republican Party after 2009 was driven by candidates who won very low-turnout primaries. We’re talking 12% to 15% turnout. This is true of the Democrats, too. In 2016, Alexandria Ocasio-Cortez, a leading voice of the party’s left wing, won her primary against the incumbent Joe Crowley, a moderate Democrat, with an 11% turnout in New York’s 14th congressional district. 

What changed about primaries to make them so polarizing?

What’s changed is the steady increase in safe seats for the both parties in the House and Senate. If a seat is safe for the party, this means that the only election that matters is the primary. That’s what produces polarization: The primary voters are pulling candidates toward the fringes. If you ignore your party’s fringe, then you’ll get knocked off in the primary. It creates incentives to demonize opponents and embrace extreme policies. 

It used to be true that politicians in Congress were more polarized than the electorate. In recent years the electorate has also become more polarized. Frances Rosenbluth and I are examining this dynamic with our research group at the Jackson Institute for Global Affairs on effective democratic governance. People think that politicians respond to voters, but that’s an artificial view of how voter mobilization works. Actually, politicians frame issues for voters. 

How does that play out in elections? 

Well, it’s not as if there were 63 million people in America in 2015 saying, “Gee, wouldn’t it be great if some candidate would call for building a wall on the border with Mexico?” That’s not how people get mobilized. What happened was that a candidate emerged who was telling financially insecure and politically alienated people that their jobs were going to Mexico, immigrants were causing crime, that self-dealing elites were ignoring this, and we’ve got to do something about it. Angry, vulnerable people then embraced that message. In other words, voters’ preferences don’t fall out of the sky. Voters are mobilized by political entrepreneurs. 

What’s the focus of your current research amid this intensifying polarization? 

We’re studying this as a two-step process. The primaries and caucuses pull the candidates to the extremes, but they want their party to win in the general election. They know that if they move to the center, they’re going to get attacked in the next primary. So instead, they try to move more moderate voters toward the extremes, so that there will be less pressure on them from party leaders to moderate their views once elected. In this way, the polarization of Congress didn’t follow the polarization of the population, it preceded it. Think of it as push-polling writ large. Candidates get pulled to the extremes by primary voters and then attempt to mainstream those extremist views to make it easier for their party to win the general election. 

At the presidential level, primaries only became important in the 1970s, but a similar dynamic operates. Consider Trump. In 2016, the Republican establishment could not stop him. They had 16 candidates and they would have taken almost any of the others over Trump. But they couldn’t prevent his mobilizing primary voters with promises to build his wall for which Mexico would pay, end illusory increases in crime and illegal immigration, restore obsolete mining and manufacturing jobs, and other things he wasn’t actually going to be able to do. Our basic problem is that weak parties are vulnerable to hostile takeovers of this sort. 

How did all the safe seats develop?

It’s a combination of things. It’s partly demographic sorting. Urbanization creates blue cities in red states, producing non-diverse constituencies. Partisan gerrymandering compounds this, as parties create safe districts for themselves when they control state legislatures. By the way, we also get bipartisan gerrymandering, where the parties cut deals and carve up the states into safe districts for each. Majority-minority districts have the same effect: The price of increasing minority representation in this way is that districts become more politically homogeneous. The net effect is more safe seats, which make the party primaries all the more important. 

The Electoral College has come under criticism from the left for being anti-democratic and facilitating Trump’s election. Would the country be better off without it?

It is understandable why people want to abolish the Electoral College. They think it systematically disfavors the Democrats because it empowers predominantly southern, predominantly rural, predominantly Republican states. Hillary Clinton would have won in 2016 if we didn’t have the Electoral College. Without it, there would be no issue about Biden’s victory, but he’s going to win anyway.

Here’s the cost of getting rid of the Electoral College: If you think the basic institutional dysfunction in American politics is weak parties in the legislature, strengthening the independent legitimacy of the president would make them even weaker. The direct election of the president would make our system more like Argentina’s or Brazil’s. The president would find it easier to insist that “only I have been elected by the American people.” This is catnip for populist candidates. It enhances executive power, further weakening parties in the legislature.  

How could the nomination of populist candidates be avoided?

Before the 1830s, the congressional parties chose the presidential candidates. It made the U.S. operate more like a parliamentary system because these congressional caucuses would pick candidates who they believed they could run and win with. America’s first populist revolt began when Andrew Jackson attacked this system as a bastion of Eastern elites after it declined to select him in 1824. In the early 1830s it was replaced by party conventions. I would much like to see us return to giving the congressional parties a bigger role in picking presidential candidates. In 2016, there is no way the congressional Republicans would have chosen Donald Trump. They would have gone for Jeb Bush or someone like him. 


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