How does giving out more visa/green cards create more jobs for Americans?

[Mr Khan]

richardhutnik said:

SamuelRSmith said:
Because increased skilled labourers increase the number of jobs available - both skilled and unskilled.

Clarify context you mean that, as if you mean a company hiring skilled labor will demand more labor, or do you mean the economy on the whole, because hiring skilled labor means that one person gets a normally higher paying job and that means they have increased demands put on the economy, which generates activity that requires increased hiring?  Second, post some evidence to back up your claim.  

Highly Skilled labor is the root of productivity, since they're the kinds that invent new products and increase productivity on existing ones, and thus make room for the business to expand and hire semi-skilled or unskilled labor, as well as peripheral employees (from human resources to janitors and everything in between)