Mr. Christie has secured labor support, especially among construction and trade unions, by emphasizing restraints on government spending, caps on tax increases, incentives for job creation, and vigorous rebuilding after Hurricane Sandy. Jobs are crucial in a state with an 8.5% unemployment rate. Mr. Christie’s message? “In four years, what I’ve really cared about is how to get you guys back to work,” he told the International Union of Operating Engineers in June.

The message resonates. When the International Brotherhood of Electrical Workers Local 102 endorsed the governor this year, “It was an easy call,” said Patrick Delle Cava, the local’s business manager. “Our men love him.” He noted that the hours his members worked under the state’s two previous Democratic governors slumped to three million in 2009 from 6.5 million in 2001. Since Mr. Christie took office in early 2010, workers have regained nearly half…

Mr. Christie has retained union support despite vetoing a bill in January to raise the minimum wage by $1.25 to $8.50. He also vetoed legislation this summer to let municipalities request bids only from all-union contractors when rebuilding after Sandy.

The larger question is what Mr. Christie’s appeal to labor might mean for his presidential aspirations. “One of the tectonic shifts in politics right now is the separation between some fiscal conservative Democrats and public-sector unions,” says Pete Peterson, executive director of the Davenport Institute at Pepperdine University. Mr. Peterson points to battles in California cities between Democratic mayors and public labor groups over government budgets and worker benefits.