WSJ’s Monica Langley profiles Corey Lewandowski, the campaign manager for Donald Trump’s unconventional presidential run.

From the Wall Street Journal:

CONCORD, N. H.—In a stairwell behind the stage as Republican presidential candidate Donald Trump spoke at a packed rally recently, campaign manager Corey R. Lewandowski lashed out at his New Hampshire state director.

“My boss is working 20-hour days; you’re not,” Mr. Lewandowski said. “You’re not meeting any of your metrics with the primary three weeks away.”

In the motorcade afterward, Mr. Lewandowski called a longtime aide supervising another state: “Fly here tonight and take over.”

With that and other late moves, the 41-year-old campaign manager helped assure Mr. Trump’s decisive victory Tuesday in the nation’s first primary. It was a crucial win for the billionaire businessman after a disappointing second-place finish in Iowa, but it was a do-or-die moment for the relatively anonymous Mr. Lewandowski, who calls the state home and was prepared to resign if his boss lost the primary.

“Corey has tremendous energy, a wonderful vision for politics and the greatest candidate ever, without which none of it works,” Mr. Trump said in an interview Wednesday as he left for South Carolina.

As the campaign moves south, Mr. Trump will face renewed resistance in his party; an anti-Trump GOP super PAC is planning an ad blitz there. Meanwhile, the GOP field is narrowing, as New Jersey Gov. Chris Christie and former Hewlett-Packard CEO Carly Fiorina suspended their campaigns Wednesday after finishing sixth and seventh in New Hampshire. That still leaves four candidates—Sens. Ted Cruz and Marco Rubio, Ohio Gov. John Kasich and former Florida Gov. Jeb Bush—battling to derail Mr. Trump.

For Mr. Lewandowski, the question is whether he can help his candidate replicate the appeal across demographic and income lines that propelled him to victory in New Hampshire, and continue to improve the campaign’s turnout operation. Mr. Trump acknowledged his ground game wasn’t strong enough in Iowa. In his Tuesday victory speech, Mr. Trump credited Mr. Lewandowski with fixing that ground game in New Hampshire, then recognized him from the podium.

The playbook for Mr. Trump’s double-digit first-place finish here, according to Mr. Lewandowski, has been the theory of the campaign from day one and will continue going forward: “Let Trump be Trump.” Those words have been scrawled on his office white board since Mr. Trump announced his run June 16.

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