The biggest threat to simple repetitive manual labor based manufacturing is robotics. The US has seen that type of domestic manufacturing decline to almost noth

The biggest threat to simple repetitive manual labor based manufacturing is robotics. The US has seen that type of domestic manufacturing decline to almost nothing over the last 30 years. China by far and away dominates that. High level manufacturing could certainly be threatened by robotics, but labor in the US is a much smaller portion of costs when you're talking about jet engines or medical devices than sewing a shirt (eg if you're paying $80k per year for labor, you're not going to be making $7 toasters in the US at that rate, you're going to be making million dollar jet engines; and you can't get labor costs below around $22,500 total in a manufacturing environment in the US). The US lost the garment industry because its labor couldn't compete on wages. The average garment worker in China isn't making anywhere near $7.25 per hour, which is the US Federal minimum wage. Legally the US literally can't compete on wages.