The penalties can now tehnically be up to $10,000 per illegal. However, every time the Feds raid a meatpacker, construction company or retail chain, the CEO of that company goes crying to their Congressman (whether Republican or Democrat) and the Congressman makes the raids stop.
The supply of illegals will never go down unless the demand for their labor decreases.
There's another problem: juries have refused to convict, even with very solid evidence.
Thank you. And every illegal hired means a citizen flipping burgers or even not working at all.