Matthew Dallek’s “Birchers” traces how conspiracy theories went from being a fringe pastime to the right’s defining feature.

Is the Republican Party compatible with democracy?

In his lifetime, Robert Welch toiled in the mocked and marginal fringe. Today his ideas are the mainstream of the American right.

Why it’s foolish to think the modern GOP will ever break with its lunatic fringe

President Eisenhower inherited a GOP that looked much like today’s—but he tamed the extremists and led as a moderate conservative.

Have historians of the conservative movement focused too much on its intellectuals?

One of its founders asks what went wrong.