A full 50 percent of President Trump’s supporters now believe the bizarre, false claims about an international ring of child sex traffickers at the core of the extremist conspiracy theory known as QAnon, according to a new Yahoo News/YouGov poll — a disturbing sign of how susceptible partisans have become to bogus stories in an age of rampant polarization and unbridled social media.

The survey, which was conducted from Oct. 16 to 18, shows that most registered voters (55 percent) say they’ve never heard of QAnon, including 44 percent of Trump supporters. And 59 percent of voters who have heard of QAnon describe it as “an extremist conspiracy theory with no basis in fact.”

Yet these numbers understate the degree to which awareness and even acceptance of QAnon’s underlying falsehoods have permeated the right, regardless of how many unwitting adherents explicitly realize such fictions originate with QAnon itself.