They should take it.

“The experience of being disastrously wrong is salutary,” John Kenneth Galbraith wrote. “No economist should be denied it, and not many are.”

I’m not an economist. But I was wrong about the litigation to bar Donald Trump from the ballot as an insurrectionist. I wrote in August that the project was a “fantasy.” Now, by a 4–3 vote, the Colorado Supreme Court has converted fantasy into at least temporary reality.

The Fourteenth Amendment provides that anyone who swore an oath to support the Constitution of the United States, and who then “engaged in insurrection or rebellion against the same,” is forbidden to hold any federal or state office unless pardoned by a vote of two-thirds of both houses of Congress.

I doubted that any contemporary court would apply this Civil War legacy to the politics of the 2020s. Colorado’s supreme court just did. Trump swore an oath to the United States when he entered the presidency in 2017. According to Colorado’s court, his actions leading up to the violent coup attempt of January 6, 2021, amounted to “engaging in” an insurrection. Therefore, the court ruled earlier today, Trump is disqualified from appearing on the Republican primary ballot in Colorado.

The Colorado decision is not the final word. The Colorado Supreme Court is the ultimate word only on Colorado law. In this case, however, the Colorado court is interpreting a federal constitutional........

© The Atlantic