Greg Weiner writes for The Atlantic about assumptions surrounding final arbitration of thorny constitutional disputes.

Americans deeply disagree on the substance of many constitutional issues. Does the Second Amendment cover semiautomatic rifles? Does a woman have a constitutional right to an abortion? But there is one area of broad agreement: The Supreme Court will have the final say, like it or not.

“Let’s let the courts decide whether it’s constitutional. That’s not for Congress to decide, that’s why we have courts to make that decision,” said Representative James Clyburn, a South Carolina Democrat who had himself taken an oath to uphold the Constitution, in 2014, when President Barack Obama faced constitutional scrutiny over a forthcoming executive order protecting millions from deportation. Similarly, Mitch McConnell, the Republican and Senate majority leader from Kentucky, was initially skeptical of President Donald Trump’s plan to stop immigration from a series of Muslim-majority countries. But he was content to punt: “Ultimately it is going to be decided in the courts as to whether or not this has gone too far.”

This consensus around judicial authority—which raises the question of why members of Congress take an oath to the Constitution if it is up to someone else to uphold it—would surprise the constitutional Framers. For them, constitutional politics—the institutional rivalries that maintain the separation of powers, and the public opinion that supervises them—played an essential role in both interpreting the Constitution and inhibiting judicial abuses. James Madison thus wrote that giving the judiciary the last word on constitutional questions “was never intended, and can never be proper.”