When considering the Democrats’ high-minded arguments, ask yourself: What if Hillary Clinton won in 2016? After she took office, it would have been revealed that her campaign hired the opposition-research firm Fusion GPS, which assigned Christopher Steele, a former British intelligence official, to reach out to Russian counterparts to solicit dirt on Donald Trump. Recall that the since-discredited dossier Mr. Steele peddled to the media in the fall of 2016 was made up of unsubstantiated rumors from former Russian agents.

It’s naive to believe the Kremlin was unaware that Mr. Steele asked Moscow pals for dirt on Mr. Trump. Those spies are retired, but they rely on Vladimir Putin for their pension checks. Who among congressional Democrats would now be calling for Mrs. Clinton’s removal if she were in the Oval Office? I doubt any. I’ve searched in vain for Democratic criticism for her soliciting foreign involvement in the 2016 election—the principal charge of their impeachment case against President Trump.

Furthermore, while Democrats say Mr. Trump should be removed for seeking a quid pro quo—a Ukrainian investigation of Joe and Hunter Biden in return for U.S. military aid—what about President Barack Obama’s March 2012 open-mic moment?