The Texas senator's own politics of racial division seem somewhat palatable by comparison.

Even Republicans are getting in on the act. But the issue's reach is still limited by age-old political realities.

The left nailed the pathology of the conservative movement years ago. The Donald is just making that impossible to deny.

Joseph McCarthy and Charles Coughlin were prominent at a time when American institutions still wielded clout.

Will their heated attacks lead to mutual assured destruction? Or will one emerge victorious?

While moderates languish in the polls, Ted Cruz and his ilk are doing just fine.