A Republican Debate Divided: the Leaders and the Rest

There wasn’t one Republican presidential debate going on Thursday night in South Carolina, but rather two. And in that sense, the debate neatly and succinctly summarized this year’s unusual race.

The first debate was between the two unlikely front-runners, Donald Trump and Ted Cruz. After months of dancing around each other—and in some cases essentially supporting each other—in crystallizing antiestablishment anger, the two now know they are fishing from the same pond with less than three weeks to go before voting begins. And they conducted themselves accordingly.

The night’s second,...