evidence: I take up this question in my recent book, "The Government’s Speech and the Constitution." It’s not that surprising that public servants lie – they are human, after all. But when an agency or official backed by the power and resources of the government tells a lie, it sometimes causes harm that only the government can inflict. [...] When public officials speak in these ways, they undermine public trust and frustrate the public’s ability to hold the government accountable for its performance. But they don’t necessarily violate any particular person’s constitutional rights, making lawsuits challenging at best. In other words, just because the government’s lies hurt us does not always mean that they violate the Constitution. [...] It can be hard to prevent government officials from lying, and difficult to hold them accountable when they do. But the tools available for doing just that include not only the Constitution but also persistent pushback from other government officials, the press and the people themselves.