Iowa Secretary of State Matt Schultz told The Des Moines Register he may sue to try to get access to a federal database so he can cross-check his list of suspected illegal voters.

Schultz has discovered there are 3,582 people who weren’t U.S. citizens when they got their Iowa driver’s license, but they are also registered to vote in Iowa. A judge late Friday issued a temporary injunction that prevents Schultz from taking any further action. Schultz spoke about the issue last week during a legislative hearing.

“When somebody casts a ballot, you can’t unring that bell,” Schultz said. “If somebody is ineligible to vote and they cast a ballot that’s been counted, we can’t take that back. This is an important election coming up — every election’s important — but there’s a lot of importance placed on this election and, you know, we were under a situation where we had these kind of numbers and we can’t be for sure whether they’re accurate or not.”

Schultz wants to cross-check his list with the federal database, to see if some of the nearly 3,600 people on his list have become U.S. citizens. Senator Tom Harkin brought up the issue this afternoon during a speech to fellow Democrats gathered at his annual fundraiser.

“I know that Secretary of State Schultz in this state and other Republicans in swing states around the country are embarked on a program of intimidation to keep new citizens from voting,” Harkin said.

Harkin praised the judge who issued the temporary injunction preventing Schultz from proceeding. The judge is Mary Pat Gunderson, appointed to the bench by Republican Governor Terry Branstad. In 1997 and ’98, she was hired by Republicans to serve as Secretary of the Iowa Senate. Her husband, Joe Gunderson, was the Republican candidate for attorney general in 1994.

In a written statement issued Friday evening, Schultz said while he is “very disappointed” by the ruling, it is “just one of many steps in the litigation process.”