The irony of this contretemps is that it concerns Giuliani, a man with a robust false-news output all his own. As The Post reported in October, the White House was warned that Russia had targeted Giuliani as a conduit for misinformation intended for Trump. The warning related to Giuliani’s 2019 activities in Ukraine, when he sought to dig up damaging information on Joe Biden and his son, Hunter Biden. Those efforts backfired, ending in Trump’s first impeachment proceedings. Giuliani moved on to sow falsehoods about the 2020 presidential election on behalf of Trump, sealing his descent into public disgrace.