Will the left go too far?

Finally, and most radically, Democrats could follow Roosevelt’s example and try to pack a recalcitrant Supreme Court. The idea, which Democrats barely discussed before Trump’s election, is gaining steam. In recent months, writers for The Washington Post, Vox, The Intercept, the Los Angeles Times, The New Republic, and The American Prospect have either endorsed it or declared it worthy of serious debate.

Advocates for overturning the filibuster and packing the Supreme Court argue that both institutions flout the popular will. Republican senators disproportionately hail from less populous states. Four of the five conservative justices were appointed by Republican presidents who’d lost the popular vote. As an article in the influential socialist journal Jacobin recently argued, “Sometimes you have to break the rules to create a more democratic system.”

In the short term, this strategy could work. Legal historians debate how much Roosevelt’s court-packing plan contributed to the Supreme Court’s decision to reverse itself and uphold the New Deal. But Chief Justice Charles Evans Hughes clearly worried that “increasing outside criticism” threatened the Court’s legitimacy. If the left can mount sufficient pressure in the future, the current chief justice, John Roberts, whose fears for the Court’s reputation may already have contributed to his refusal to strike down the Affordable Care Act, might bend too.

But another lesson of the 1930s and the 1960s is that threatening entrenched norms and disrupting public order—although effective for a while—can eventually provoke a fierce backlash.