The left’s embrace of violence has reached the edge of the cliff. “The ultimate source of political power is, and always will be, violence,” George Mason University graduate student Nicholas Decker posted, promoting his recent Substack titled “When Must We Kill Them?” Decker is working on his PhD in economics, but his post had nothing to do with President Trump’s economic policy. Instead, it was a fantasy piece about the left murdering Trump administration officials, including Trump, over some perceived attack on Americans’ freedom. “Evil has come to America,” Decker said. “The present administration is engaged in barbarism; it has...