In response to reports that the IRS targeted politically conservative groups, Obama said he “certainly did not know anything about” the scandal before reading news reports.

“I can assure you that I certainly did not know anything about the IG report before the IG report had been leaked through the press," Obama said.

Rubio said Obama didn't answer the "very simple and straightforward question." Rubio said he should have “echoed” comments from the White House press secretary, Jay Carney, who said no one in the White House knew about the IRS's actions.

“I’m not saying [Obama] did know, but it’s best not to leave that out there,” Rubio said.

Lawmakers have called for a full investigation into the actions of the IRS. Rubio said it’s not enough that acting IRS Commissioner Steven Miller resigned Wednesday. He said there were still many questions that the administration will have to answer.

“I just want to get to the bottom of this,” Rubio said. “What can we do now to ensure that this never ever happens again … so no American feels afraid to speak out politically for fear of government action.”