Carrier isn’t changing its plans. On Friday in a written statement, the company said, “We are making every effort to ease the transition for our Carrier colleagues in Indiana.” The company pointed out that it will finance four-year retraining and educational programs for employees and provide financial help.

For Mr. Trump, now comes the hard part. In interviews in recent days and in March, Trump voters here made clear that if he does not follow through on his promises, they are prepared to turn on him, just as they are seemingly punishing Democrats today for not delivering the hope and change voters sought from President Obama after he won as an outsider in 2008.

And while Mr. Roell is a conservative, Mr. Trump’s tough talk about Carrier, the economy and the future of American manufacturing jobs also appealed to moderates like Darrell Presley, a steelworker in rural Crawfordsville, Ind., who voted for Mr. Obama in 2008. “He was for change, and said he would take care of the middle class, but he didn’t live up to those expectations,” Mr. Presley said. “I feel like the American people are at the point where they’ve had it, and this was the last chance.”

Last Tuesday, blue-collar workers across the industrial heartland hearkened to Mr. Trump’s call, putting states never thought to be in serious play, like Wisconsin and Michigan, in his win column.

As president, however, Mr. Trump will face a tough balance. Tariffs and trade wars stand to hurt American workers who make products that are exported to Mexico or China. Few voters will be happy paying more for imported goods.

And regardless of who is in the Oval Office, manufacturers are seeing relentless pressure, from investors and rival companies, to automate, replacing workers with machines that do not break down or require health benefits and pension plans. Wall Street hedge fund managers are demanding steadily rising earnings from Carrier’s parent, United Technologies, even as growth remains sluggish worldwide.