Congressional probes into Russia’s attack on the 2016 election have unearthed numerous undisclosed meetings between the Trump team and Russians with ties to Vladimir Putin, repeated Russian offers of assistance, the willingness by the campaign to accept Russian help, the provision of help by the Kremlin, and a conspiracy to undermine the penalties imposed on Russia as a result.

Notwithstanding this progress, or more likely because of it, President Trump and his allies have been pressing Speaker Paul Ryan to bring the House’s...