It's too soon to know what will define Donald Trump's presidency, but one of the defining characteristics of his campaign was a near-total disregard for facts. According to PolitiFact ("Donald Trump's file," n.d.), about 70% of Trump's statements have been either mostly false, completely false, or outright lies. Candidate Trump wasn't the only one dealing in dishonesty, but the ubiquity of falsehood surrounding his election contributed to the Oxford Dictionaries naming "post-truth" its 2016 Word of the Year. Fake news (Drobnic Holan, 2016) might be the most pernicious form of post-truth. PolitiFact called fake news its Lie of the Year, pointing out that fake news is "the boldest sign of a post-truth society" (para. 12) and that it "found a willing enabler in Trump" (para. 8). Americans should perceive this phenomenon as an existential threat to democracy. What truths remain self-evident if truth itself becomes counterfeit? A post-truth society has no moral center, no basis for conversation, no shared future. If the Trump era is to be the era of post-truth, then schools will have a particularly critical role to play in teaching students to favor reason and evidence over sentiment and preconception. More simply, we need to get better at teaching what Carl Sagan (1995) called "the fine art of baloney detection" (p. 201). Educators must also help students explore and deliberate on political issues. This article examines several particular challenges of fake news on the internet, and offers strategies and resources to support critical thinking and positive political engagement in the classroom.