The Wall Street Journal reports that Republican lawmakers are digging deeper into the actions of Thomas Perez, the Justice Department’s top civil rights attorney. They’ve issued a subpoena for emails related to a highly unusual deal he arranged with the city of St. Paul, Minn. Perez is now the White House’s nominee to be labor secretary.

The Journal notes:

The subpoena came after Republican lawmakers called attention to his use of a private Verizon email account to communicate with lawyers representing the city of St. Paul, Minn., regarding a deal that the lawmakers have sought to make an issue in his pending nomination.

As The Wall Street Journal reported last month, Justice Department emails and other documents show Mr. Perez worked to secure a deal in which St. Paul agreed to drop a Supreme Court case that threatened an enforcement policy used by the department in housing-discrimination cases. In exchange, the Justice Department declined to join two unrelated private lawsuits alleging the city made false certifications to obtain more than $100 million in federal housing funds.

Mr. Perez, the Justice Department’s top civil-rights lawyer, has turned over department emails and other documents on the St. Paul deal, and last month he answered questions from congressional investigators in a voluntary interview.

Federal law requires the preservation of records related to official business, which are easier to access on government email. Lawmakers have long expressed concern about the use of personal email by government officials to conduct official business, because those records aren’t readily obtainable.

Asked in his March 22 interview with congressional investigators about the use of personal emails in the St. Paul matter, Mr. Perez responded: “I don’t have any recollection of having communicated via personal email on this matter.”

Republican lawmakers investigating the matter said they had obtained at least one email from Mr. Perez’s Verizon account related to the St. Paul cases, and said they wanted to be sure he turned over all records.

Read the whole thing here.

For more background on the deal he struck with St. Paul, click here and then here. To understand why Perez was eager to make the deal in the first place, click here.