Immigration law provides no path to legal status for the undocumented spouse of a US Citizen.
A mandatory ten year bar on legal entry to the US before a green card will be granted means seperation of families. Citizens are the ones suffering because of this oversight.
An undocumented alien, who has no family connection or ties to the US, detained by the police for DUI then arrested and placed into the custody of ICE for removal proceedings has more opportunity. The undocumented drunk driver has only to claim 'fear' of being deported home country to be granted a day in front of an immigration judge. Since the court is so backed up, that day is years off and a work permit can be obtained meanwhile.
So DUI arrests provide a path to legalization but marriage to a US citizen does not.