Ravin Gandhi, founder and chief executive of GMM Nonstick Coatings in Chicago, is a case in point.

The son of immigrants from India, Mr. Gandhi fiercely opposed Mr. Trump before the election, even appearing on CNBC to denounce the candidate’s proposals on trade, immigration and health care.

After Mr. Trump was elected, however, “I bought into the economic growth rhetoric,” Mr. Gandhi said. “I was hearing stories about 4 percent growth, about tax reform and my health care costs going down.”

None of that has come to pass, of course.

But this year Mr. Gandhi has invested $3 million to expand domestically and hired more than 20 employees, even though sales are flat compared with 2016, when they were up by double digits.

“It’s nuanced,” he said, noting that his company was recently purchased by a Japanese conglomerate and that the American houseware firms he supplies make their pots and pans mostly overseas.

“A lot of us who were against Trump are still rooting for him to succeed because as citizens we want the economy to do well,” Mr. Gandhi said. “But so far, it’s been all hat and no cattle.”

Despite generally strong earnings, many manufacturers continue to shed jobs.

In December, Mr. Trump persuaded United Technologies, parent of Carrier, not to proceed with a shutdown of an Indianapolis plant, but the company did go ahead with several hundred previously announced layoffs last month.