DUI conviction for alien resident, would marriage to a U.S. citizen allow alien to stay in the U.S.

You will need to provide some more information in order to get any valuable input on this case. It is not clear from your question what the immigration status of your partner is. I would assume that he entered the country illegally or was otherwise out-of-status since he was sent to an immigration jail. Knowing his current immigration status is critical to determining what remedies, if any, might be available. It is also important to know whether you are a U.S. Citizen. Feel free to email me with some more information and I'll try to give you a little more guidance. Thank you for your question.

Normally, drunk driving is not a deportable offense. I'm not sure what you mean by his "bond" . . . Immigration Bond, or DUI Bond? If your partner is out on an immigration bond, then he is already in immigration proceedings and marriage to a US citizen will not help him. If it is only a DUI bond, talk to a qualified immigration lawyer and provide him with the facts you did not provide in your question and then he/she can answer your specific questions.