Bangladesh, Sept. 13 -- For years, Democrats warned Americans that foreign interference posed an existential threat to the integrity of US elections. They invoked Russia, intelligence agencies and national security to justify investigations into Donald Trump's 2016 presidential campaign. Yet the political establishment that demanded extraordinary vigilance against foreign influence now appears far less concerned when foreign nationals and noncitizens become useful to Democratic political interests.

That contradiction deserves scrutiny.

The Russia-collusion saga became one of the defining political controversies of the Trump era. Democrats repeatedly argued that alleged foreign interference demanded the most aggressive possible response...