If Pete Buttigieg beats Donald Trump in 2020, he’d support a criminal investigation into the former president.

“To the extent that there’s an obstruction case, then yes, DOJ’s got to deal with it,” the South Bend, Indiana, mayor said yesterday, during a meeting with Atlantic editors and reporters. Citing Gerald Ford’s pardon of Richard Nixon after Watergate, Buttigieg said he would not be interested in doing the same for Trump.

“I would want any credible allegation of criminal behavior to be investigated to the fullest,” Buttigieg said—something a pardon would preclude.

Over the past two months, the 2020 Democratic primary candidates have been wrestling with the question of impeachment, as they try to balance just how much they should talk about Trump. Pressure, however, continues to build: Many base voters are continuing to call for impeachment, with more than 60 House Democrats trying to pressure their leaders to begin hearings. And that pressure has only increased since Special Counsel Robert Mueller went on television two weeks ago and repeated what was written in his report: that while he did not consider criminal charges because of a Justice Department policy that bars the indictment of a sitting president, if his team “had had confidence that the president clearly did not commit a crime, we would have said so.”