It is argued that the Democrats want the illegals to stay in country due in part to gaining their vote. There is truth to that for sure, yet advocacy organizations raise a LOT of money which is in the end more important to the Democrat base for campaign contributions.
For a list of pro-amnesty groups covering all industry and social classifications, go here.
Perhaps as a reminder it is prudent to mention that Obama led the charge for clemency and pardons as noted here.