Scott Alexander reviews Why We’re Polarized by Ezra Klein, beginning with the underpolarization crisis of the mid-20th century:
In 1950, the American Political Science Association “released a call to arms … pleading for a more polarized political system”. The report argued that “the parties contain too much diversity of opinion and work together too easily, leaving voters confused about who to vote for and why”. Everyone agreed with each other so much, and compromised so readily, that supporting one party over the other seemed almost pointless.
In 1976, three years after Roe v. Wade, Democrats and Republicans were about equally likely to support abortion restrictions. That same year, a poll found that “only 54% of the electorate believed that the Republican Party was more conservative than the Democratic Party”; 30% thought there was no difference. As late as 2004, about equal numbers (within 5 pp) of Democrats and Republicans agreed with statements like “government is almost always wasteful and inefficient” and “immigrants are a burden on our country”. Between the late 60s and early 90s, Democratic presidents deregulated the airlines and passed welfare reform; Republican presidents pushed immigration amnesties and founded the EPA.
What happened between then and now? Klein has two answers: a historical answer, and a structural answer.
The historical answer is: the Dixiecrats switched from Democrat to Republican.
When the North won the Civil War, it had grand plans to remake the South into a paradise of racial equality and universal love. After Lincoln’s death, his successor Andrew Johnson decided this sounded hard and gave up. Within a few decades, the South was back to being a racist, paramilitary-violence-prone one-party dictatorship. That one party called itself “Democrat”, but had few similiarites to the Democrats in the North. The Southern Democrats (“Dixiecrats”) and northern Democrats disagreed on lots of issues, but the South hated the Republicans so much after their experience with Lincoln that they caucused with the northern Democrats anyway. This turned into a stable coalition, with northern Democrats agreeing to support the South against civil rights for blacks, and the Dixiecrats supporting the northern Democrats whenever they needed something.
But since the Democratic party contained both northern Democrats (relatively liberal) and Dixiecrats (relatively conservative), it didn’t want to take a coherent party-wide stance on liberalism vs. conservatism. And by the median voter theorem, that meant the Republicans also didn’t want to take a coherent stance on liberalism vs. conservatism. So both parties ended out centrist and identical.
In 1964, the Civil Rights Act threatened the Dixiecrats’ key issue. It wasn’t quite as simple as “Democrats were for it, Republicans were against it” – in fact, 80% of Republicans and 60% of Democrats supported it. But that year’s presidential election pitted heavily pro-CRA Democrat Lyndon Johnson against anti-CRA Republican Barry Goldwater, beginning Southerners’ defection to the Republican Party.
Klein says this successfully got all the conservatives on one side of the aisle and all the liberals on the other, allowing polarization to begin. Essentially, he believes polarization is a natural process, which the odd coalitions of the early 20th century temporarily prevented. Once the coalitions were broken, it could begin to do its work. He spends the rest of the book talking about why exactly polarization is so natural, what aspects of modernization have made it worse, and what sort of feedback loops make it keep going
