Students who smoked were very eager to tune in to the speech that suggested cigarettes might not cause cancer, whereas nonsmokers were more likely to slam on the button for the antismoking speech.

There are facts, and there are beliefs

In one particularly potent example of party trumping fact, when shown photos of Trump’s inauguration and Barack Obama’s side by side, in which Obama clearly had a bigger crowd, some Trump supporters identified the bigger crowd as Trump’s. When researchers explicitly told subjects which photo was Trump’s and which was Obama’s, a smaller portion of Trump supporters falsely said Trump’s photo had more people in it.While this may appear to be a remarkable feat of self-deception, Dan Kahan thinks it’s likely something else. It’s not that they really believed there were more people at Trump’s inauguration, but saying so was a way of showing support for Trump. “People knew what was being done here,” says Kahan, a professor of law and psychology at Yale University. “They knew that someone was just trying to show up Trump or trying to denigrate their identity.” The question behind the question was, “Whose team are you on?”

It will require a struggle to make America reality-based again. Fight the good fight in your private life. You needn’t get into an argument with the stranger at Chipotle who claims that George Soros and Uber are plotting to make his muscle car illegal—but do not give acquaintances and friends and family members free passes.

“You are entitled to your own opinion, but you are not entitled to your own facts.”