Donald Trump has built his leading position in the Republican primary race by bringing together an underappreciated segment of the GOP—blue-collar voters who aren’t especially animated by social issues—and who may be setting the stage for an unusual, three-person sprint to the nomination.
Mr. Trump’s appeal is a form of secular populism rarely seen in Republican primary races, and one he is pressing in part with appearances in working-class communities in Iowa that include independent voters and even Democrats who may be lured into the caucuses. The celebrity businessman’s message appears to resonate among voters who believe most strongly that political leaders are unable to put the nation back on track. ...