South Carolina rode the manufacturing recovery hard, and it resulted in a sharp decline of the unemployment rate.
But on Monday, a key measure of U.S. manufacturing fell to its lowest level since June 2009.
The Institute for Supply Management said its reading of factory activity fell to 49 last month from 50.7 in April -- the first time the index has been under 50 since November. Below 50 means the manufacturing sector is contracting.
The May reading "was not only weaker than expected, but it also showed a poor performance across the board," said Martin Schwerdtfeger, senior economist for TD Bank.
Still, "a month of data does not a trend make," he said. "Given that new orders are still in expansion territory and the global backdrop of manufacturing is improving, May's U.S. manufacturing weakness might well be a blip and not turn into a summer lull."
South Carolina may weather the slowdown better than many top-heavy manufacturing states because the heaviest of its factory employers -- BMW, Michelin, GE and Boeing -- are global leaders in what they produce.
"BMW was basically undeterred by the Great Recession, unlike most other auto producers, and has continued to expand with the addition of new lines," said Clemson University economist Bruce Yandle.
"Boeing gives a strong connection to the developing world, and BMW is no piker on this score. Between the two, and others in the state -- tires is another good example -- we are riding a bit of a crest."
That doesn't mean South Carolina's manufacturers are immune from global conditions, Yandle said.
"Now, of course, Europe is getting even slower, the developing world is slowing and the U.S. economy is taking it on the chin, which means South Carolina will dip a bit, too," he said.