There's no such thing, in 9999 out of 10000 cases, as a 'Labor Shortage'. Let's do a thought experiment here. If you offered $30 an hour plus benefits to do home construction, would you have any 'shortage' of skilled applicants?
Absolutely not. What the homebuilders mean by this is that they're upset that they'll have to offer more to workers to get them to accept their terms of employment. Poor babies. Piss on them and their abuse of both moral language and the language of economics to get their who...whom concerns advanced. And to hell with the supposedly liberal SF newspapers for giving them an uncritical trumpet---or is it strumpet, with which to advance their deceit.
How about this headline:
Immigration enforcement allows indigenous American workers to command higher wages in the construction industry, strengthening their marriages and position in the MMP/SMP.