The mob that attacked the Capitol on Jan. 6 had a very specific goal. It wanted to pressure Vice President Mike Pence into delaying the certification of President Joe Biden’s electoral victory by exploiting ambiguities in the Electoral Count Act of 1887.

Pence, to his credit, resisted this pressure, but the danger of a future vice president being less principled remains. Yet Democratic leaders are refusing to work with Republicans to fix this loophole.