"Long and difficult process" doesn't even begin to describe how hard it is, its impossible to get in this fucking country. The best way to do it is to get a student visa, stay, and get married to a citizen. Plain and simple. Maybe if the US wasn't so anti-immigration, there wouldn't be as many people doing it the illegal way. The laws here and loopholes that hold you back are insane. Also, I am a white European, would they really stop me and ask me for my status? No, because I don't look Mexican. This is a law against Mexican illegals, not all illegals.
Just because immigrants like myself are willing to do the shit jobs that pay shit to make it doesn't make immigrants bad. I don't hate people who play the system cause I played the system too, a majority of immigrants like me had to work around the system to stay here, not because we want to, but the other option is way too expensive and complicated. I have loads of friends who got married for a passport, its normal where I live. By making the process so difficult, the US only makes immigrants look for other routes towards citizenship.