I’m honored by the esteemed Professor Josep Colomer praising Parliamentary America. He commends my “good use of political economy, social choice theory, and comparative politics;” describes the book as “didactical, with a practical purpose” and “academic” in the best sense; and calls my proposals “highly relevant,” “timely,” and “a welcome addition to an urgent debate.”

Despite common ground, our differing perspectives emphasize competing concerns. Colomer and I agree two-party presidentialism, replicated nowhere despite its remarkable longevity in the United States, is the root of our constitutional crisis. We agree that where we end up depends on where we started (see his note about “the present past” and Douglass North). And we recognize the need for buy-in among politicians with blocking power.

Colomer levels two central criticisms: first, that I treat the United States as “one more nation-state analogous to the largest countries of Europe,” giving inadequate attention to federalism (I don’t), and second, that I contravene the cube-root rule (I do). I criticized Colomer’s Constitutional Polarization for not prescribing a remedy worthy of its bold diagnosis and for embracing proposals that can’t solve the crisis or be enacted. The ultimate question remains: “who’s right?” I remain confident Parliamentary America makes the stronger case.

My virtual world tour—England, France, Germany, Israel, Taiwan, Venezuela, and Brazil—doesn’t treat the United States as any foreign nation. It shows that avoiding the twin threats to democracy—either too few or too many parties—demands revisiting choices along two key democratic axes, namely how we elect the House of Representatives and the manner of presidential selection and accountability.

Although my proposals place separation of powers at center stage, they are sensitive to federalism, with discussions of these dynamics interspersed throughout. I observe that overcoming the first two constitutional crises transformed federal-state relationships (pp. 23–24); that modern affinities are regional (pp. 247–50); and, contrary to Colomer, that U.S. state sovereignty has long been constrained (p. 248).

Federalism rarely defines our most divisive issues—e.g., guns, racial justice, reproductive rights. But it does play a central role in existing institutional arrangements, explaining the Senate’s egregious representational disparities (pp. 247–50). That’s why, despite suggesting possible future Senate reforms (pp. 284–87), my amendments leave that body intact. My proposals will undoubtedly affect federal-state dynamics, but Colomer offers little beyond speculation as to how this threatens Parliamentary America.

Colomer acknowledges the importance of political buy-in for reform but disregards my explanation that the cube-root rule defeats it (pp. 183–84, 250–52). His alternative, adding 265 seats to achieve 700, rather than doubling the size of the House to 870, does as well. Representation demands whole numbers. The party effects of Colomer’s district magnitude calculations are inconsequential. What’s not is allocating 265 seats across fifty states. With required equal-population districts, his scheme will intensify opposition among small states whose populations disallow more seats. Doubling avoids that.

Colomer disregards that even an 870-member House leaves our constituency-to-representative ratio extraordinarily high globally, beyond India. Parliamentary America won’t add new constituencies or “territorial demands.” But introducing more, but not too many, parties with greater discipline counters decision costs, averting unmanageable administrative burdens.

Professor Colomer’s thoughtful review sharpens the debates over reforms claimed to end the threat to U.S. democracy. Along with Colomer, I hope for further vital conversations.