Capitalist societies should never have subsidies for labor, but subsidies aren't what makes Mexican labor cheaper when it comes to, say, strawberry picking. By and large, Mexicans are willing to do the job cheaper. So let 'em.
But look: you're not going to convince me otherwise. Sorry--you don't get some sort of special prize for being born in America in my book. I said level playing field and I meant it; that doesn't include subsidies, but that also means a free labor market--and that doesn't include artifical restrictions from Congress.
America belongs to Americans, period. The "rights" of illegals ends at the border.