The drunken-driving case seemed straightforward, the kind that prosecutors in Seattle convert into a quick guilty plea hundreds of times a year: a swerving car, a blood-alcohol level more than twice the legal limit, a first-time offense that caused no injuries.

The only complication was the driver. A 23-year-old undocumented immigrant studying at the University of Washington, she had gained some assurance against deportation through a federal program for people who had entered the country illegally as children. If she pleaded guilty to driving under the influence, the punishment any Washington resident might face could be compounded by a more permanent penalty. She could lose her protected status; she could be deported.

Read more in The New York Times.