Both parties have been flooding the US with both legal and illegal immigration, and it doesn’t just impact unskilled workers.
Again, try paying your plumber minimum wage and get back to us.
If you develop a marketable skill, you can market it at market rates. If you don’t have any marketable skills, you need politicians to set your rates and you are screwed because the people paying your salary will always buy off the politicians to keep your rate low.
Average Plumber Hourly Pay = $21.11
That is not great money.