Political parties, and their travails, have been much on my mind recently as I speak to radio and television interviewers about my new book, How America’s Political Parties Change (And How They Don’t). The book’s thesis has been that our two parties, founded in 1832 and 1854, have often changed issue positions but have retained their basic character in a nation that has expanded from 25 million to 325 million people.

The Republican Party has always been centered around a constituency of people thought of as typical Americans but who are not, by themselves, a majority. The Democratic Party has always been a coalition of disparate groups not considered typical Americans but who, when they stick together, can form a majority.