As former President Donald Trump dominates the Republican presidential primary, some liberal groups and legal experts contend that a rarely used clause of the Constitution prevents him from being president after the Jan. 6, 2021, attack on the U.S. Capitol.

The 14th Amendment bars from office anyone who once took an oath to uphold the Constitution but then “engaged” in “insurrection or rebellion” against it. A growing number of legal scholars say the post-Civil War clause applies to Trump after his role in trying to overturn the 2020 presidential election and encouraging his backers to storm the U.S. Capitol.