If you raise the US Minimum wage to $20 an hour you will immediately see people move their companies to Mexico,China,etc.. So that will only make the problem worse. Instead of making $10 an hour those employees will be making $0.
The truth is that much of the manufacturing here in the US is already largely automated, and many of the few jobs left in manufacturing are a few higher skill positions that probably pay an hourly wage near or above $20 already. Any job that's going to be eliminated is going to be eliminated in the next few years whether you raise the minimum wage or not. Instead this argument against a higher minimum wage means that every worker who job cannot be outsourced because it is some service industry job for example is being held down financially on account of the country losing jobs that might be automated eventually anyway.
On top of that a $20 minimum wage would also probably create much more demand by many of those who today are earning less than $20 per day.