Except not really. The immigrants weren't dragged here in chains, they came of their own accord.
They are working for what they consider a fair wage.
Now, here's the thing. Before a bunch of stupid white people got all upset their daughters might be fucking Mexicans, it used to be that people from Mexico would come up, work for a few months, and then return home and live pretty well for the rest of the year on the money they made.
Then they insisted on making the border harder to cross. So eventually, those migrant workers decided to just cross the border once, and stay. Maybe bring their families with them.
Also, Americans simply don't want those jobs. They just don't. With 4% unemployment, they don't need to take them.
Now, since you brought up undocumented immigrants vs. drug users.
I worked for a company from 2002- 2008. The one where the management was so evil it cured me of being Republican. Anyway, to get around the "not hiring illegals" to do menial work, they hired these contractors through a labor agency. We started out with 2 but eventually had six. they were nice guys, did the work efficiently and they went home.
Then, a bigger company bought this one out (after I left.) and their first dictate was that contractors had to have proof of citizenship. So the Mexicans were gone and the only people they could find was these scary as hell white methheads. Didn't work half as hard. The girls in the office asked for someone to walk them to their cars at the end of the day. When Payday came, they wouldn't show up the next Monday and they got a whole new batch of scary as hell contractors on Tuesday.