It's implicit in your argument. The idea that immigration should be turned off to alleviate unemployment is a common economic fallacy, which ignores the fact that immigrants also consume and therefore create more demand and more industrial activity and more jobs. This works out nicely economically because the receiving country hasn't paid for them to be educated or nursed through childhood, so the immigrants are effectively little engines of consumption without any social debt, significantly increasing the economic benefit of their spending.
I admit that this won't make much sense if you haven't taken some economics classes, it's counter-intuitive.
Or people who come for a few years and send it all home. Or live here for years, sending vast percentages of it home.
>paid for them to be educated or nursed through childhood
We have already paid anything there we had to, so they're sunk costs for non-immigrants. The cost of aid programs, retraining and the like are pain points for non-immigrants and the government.
Economics in one of those subject matters where vast swaths of it are only taken as real by some people in the field. Without knowing exactly what you're talking about (this labor lump policy doesn't seem to be settled economics from the cites), the fact there was a class on it doesn't necessarily mean it's something we should be making decisions on.
They don't send it all home, because otherwise they wouldn't be able to live here. besides, what is sent home often creates demands for American exports.
We have already paid anything there we had to, so they're sunk costs for non-immigrants.
...apart from the interest on the debt accrued in doing so.
Economics in one of those subject matters where vast swaths of it are only taken as real by some people in the field.
OK...and it's a lump of labor fallacy, not a lump of labor policy, and it is about as settled as anything gets in economics, having been called out as a fallacy in 1891 by DF Schloss. I defy you to find me any economic theoretician who believes int he notion of a 'lump of labor'. Even labor unions, traditionally the holdouts on this issue, have abandoned this position in recent years and accepted the importance of consumption as a factor of demand.
Even if it is better to have immigrants than natives, why would H1Bs be the right way? Green cards would be better according to your theory than H1Bs. They would hurt current green card and citizen workers less as well.
I admit that this won't make much sense if you haven't taken some economics classes, it's counter-intuitive.