The lawsuit comes as the government is pursuing charges of rioting, conspiracy, and property destruction against more than 200 people arrested on Inauguration Day.
Donald Trump's supporters crowed when leaked pages of his 2005 return showed he paid a hefty amount of taxes. But the returns for the following years, which remain secret, likely include some hefty refunds of that payment.
While immigration officials announced this week they won't urgently seek to deport undocumented residents protected by the DREAM Act, the policy's future is far from certain.