There is no sector of the US economy with a genuine labor shortage - not white collar, not skilled blue collar, not unskilled. If there were real labor shortages, the unemployment rate (which only counts people actively seeking work) would be effectively zero. “Labor shortage” is upper management-speak and politician-speak for “we’d rather pay wages that Third World immigrants will accept than American wages.”
1. The unemployment rate IS effectively zero. The vast majority of people unemployed today are either unable to work or have no interest in working.
2. That's a good point about "labor shortages" by sector. I agree with you for most sectors, but what you're overlooking is that many sectors are competing for the same labor -- and collectively there actually may be a shortage across multiple sectors. I wish truck drivers could be paid as much as medical doctors, for example ... but if that were the case then there would be a "shortage" of medical doctors as many of them change careers.