Three days prior to the first debate of the Democratic Party presidential candidates, Bernie Sanders’s campaign is reminding voters Saturday that he voted in 2002 against the Iraq War, emailing out his speech of 13 years ago on the floor of the House.

Going into the faceoff Tuesday night on CNN, this email was the Sanders’ campaign effectively telegraphing its expected attack that the Vermont independent senator could use against his competitor Hillary Clinton, who voted for the Iraq War, giving George W. Bush the then president the authority to enter the U.S. into war.

The email, which came from Sanders’ Michael Briggs said the speech in 2002 shows he had the experience and judgment to make decisions on foreign policy in the country’s best interest. He called the vote on the Iraq War one of the worst blunders of foreign policy in Unites States history.

Clinton’s vote in 2002 in favor of the war hung over her for over a decade. It was one of the largest divisions between her and then U.S. Senator Barack Obama during the 2008 Democratic primary.

Liberal Democrats hit Clinton hard for the vote. Some analysts have said that was one big reason she had lost the Democratic nomination.

In a recent memoir, Clinton wrote that she should have stated her regret for the vote sooner and in the most direct and plainest language possible.

During a New Hampshire town hall earlier in October, Clinton was asked by a veteran of the Iraq War about her 2002 vote.

She said she misjudged what the president would do with it and was regrettable for the vote she made.

She said she was likely much more prepared to say no due to seeing what had been done with one vote she gave the president.

Lincoln Chafee the former Governor of Rhode Island has said during his presidential candidacy that he will use the Iraq War vote of Clinton against her as well during the debate.

Martin O’Malley the former Governor of Maryland is way behind both Clinton and Sanders in polls and will knock Clinton on her Iraq War vote.