The short answer is yes. You may even become "illegal" yourself, as marrying someone for the sole purpose of circumventing US Immigration laws is a federal offense.
There is a legal method for a citizen to marry a non-citizen, but it requires that you follow a particular procedure. If you want to marry a non-citizen, you should contact the Department of Immigration for details on how to proceed; the exact steps depend on where you'll be getting married and what the current visa status of the non-citizen is.
In any case, marrying someone does not automatically make them a citizen. It does make them eligible for permanent resident status (conditional, if you've been married for less than two years).
From what I understand, you can't marry anyone who is already married (unless they divorce their current partner or become a widow)
2 Tacos
sure whynot
No. Polygamy is illegal in Mexico.
In many places, it still is.
Yes, but the person you marry still remains a immigrant
cuz they still all the green cards
You will be an illegal alien while in Mexico. You would have to clarify your legal status before the Mexican Instituto Nacional de Migracion (National Migration Institute).
Yes, a US citizen can marry an illegal alien whose Visa has expired in San Francisco. The illegal will still have to renew their Visa to stay in the US.
No. Get married.
No. She is still an illegal alien.
Where can you marry an illegal allien?