BOSTON (AP) — Think back to America's founding fathers, and you'd be forgiven for imagining plenty of prudence and self-restraint.

You'd be wrong: A lot of riotous rhetoric sprang from those stiff upper lips. Political bombast is nothing new — it's in our DNA. But so is the concept of civility in public discourse, which sprang from the colonists' initial rough-and-tumble approach to nation-building.

Steven Bullock, a professor of humanities at Worcester Polytechnic Institute and the author of a new book, "Tea Sets and Tyranny: The Politics of Politeness in Early America," thinks we've lost our...