The Trump-Russia collusion narrative collapsed a year ago with the Robert Mueller report, but the story’s not over. Democrats are now trying to suppress details of how the bogus theory was promoted, led by House Intelligence Chairman Adam Schiff.

Republicans on the Intelligence Committee, under then-chairman Devin Nunes, wrapped up their investigation of election interference in April 2018. They found no collusion between the Trump campaign and Russians. Mr. Schiff and Democrats objected to that conclusion and accused Republicans...