I remember walking into a Walmart. All the help stocking the shelves couldn't speak English. They looked like Amerindians, the usual illegals. Big meat processing plants come to mind as using illegals. I suspect big agricultural businesses use them also. Small landscape and roofing business have no special clout with the senate and president. It's the big business that do. It's the big business that are using cheap labor. You don't have to be a union member to see this happening.
I don't have any special animus toward union labor. On most privately funded jobs they are productive. They do take advantage of public works projects but so do government officials and business owners. Union labor was steadfast in their support against Communism for most of the twentieth Century. The desired effect of bring in unlimited illegal is to kill unions and lower wages across the board. I see no one else to blame but the President and the Senate.
That's convincing evidence.
So now it's Bush, the Senate, Big Business in general, and Wal-Mart in particular that are all bad, and unions that are good?
Further, the "small landscapers and roofers" you defend aren't competing with big businesses (which you claim use illegal labor), so what forces them to hire illegals?