I think the bigger issues are that
1. There aren’t THAT many jobs in the skilled trades. Yes, there are temporary shortages in some areas, but it wouldn’t take all that many trainees in raw numbers to swamp the fields.
2. Many kids, bless their hearts, just don’t have the capabilities to do well in many skilled trades. They don’t have the mind for it, the physical endurance, or whatever else. Skilled trades can become quite intricate and complex and there are definite IQ thresholds below which people just don’t do well in them.
These are difficult issues, and lack easy solutions.
The folks you describe are the very Americans whose jobs are taken by illegal immigrants. Marco wants those illegals to get green cards and then citizenship.