President Trump has been upending the global economy in the name of bringing manufacturing back. President Joe Biden signed into law massive investments aimed at doing something similar. The American manufacturing sector is reviving after decades of decay.

But there’s something a bit weird undercutting this movement to reshore factory jobs: American manufacturers say they are struggling to fill the jobs they already have.

According to data from the Bureau of Labor Statistics, there are nearly half a million open manufacturing jobs right now.

Last year, the Manufacturing Institute, a non-profit aimed at developing America’s manufacturing workforce, and Deloitte, a consultancy firm, surveyed more than 200 manufacturing companies. More than 65% percent of the firms said recruiting and retaining workers was their number one business challenge.