The news that the FBI is evaluating additional emails relating to Hillary Clinton’s private email server rocked the race just ten days before Election Day.

But despite the tightening polls, Tim Kaine, Clinton’s running mate, said the FBI investigation has only served to energize the Democratic base in the final days of the 2016 race.

“We’ve seen it add to the energy on our side,” he told CBS’ “Face the Nation” Sunday. “People on our side view this campaign as so important, the ‘Stronger Together’ message as so important and people don’t want it to be distracted. So there has been a great uptick in energy on our side in the early vote.”

Still, asked whether the new FBI announcement has actually helped the Clinton campaign, Kaine said he believes it “is probably going to be a net wash.” The polls had already begun tightening before FBI Director James Comey’s announcement on Oct. 28 -- and that it’s a “natural” trend at the end of an election.

“I view that as kind of a natural tightening … at the end of a race,” he said. “Undecided voters, if they have a Democratic or a Republican lean, they tend to go back to their team and we are seeing that happen at the end, and so the tightening began before.”

Kaine said he and Comey had a “solid working relationship” when he was mayor of Richmond and Comey worked in the U.S. Attorney’s office, but said his decision to notify Congress of the new investigation was “puzzling and troubling.” Asked whether Clinton will be able to work with Comey, whom she and her campaign (Kaine included) have criticized for his handling of the situation, Kaine demurred and said that discussion is premature.

“That assumes something we’re not ready to assume,” he said. “We’re not assuming anything about the outcome Tuesday, we are focused on doing everything we can to win on Tuesday and then we’ll think about what happens later.”

Kaine, who was campaigning in Wisconsin Sunday, downplayed the idea that the Clinton campaign is adding Rust Belt state visits in the final stretch because it’s concerned those states are actively in peril for Clinton.

“I was in Arizona earlier this week which is a really difficult state for us but we’re making a play there and we want to do the same here in the Midwest,” he said. “The polls in Wisconsin and Michigan look favorable to us but polls can be wrong so we don’t take anything for granted and that’s why I’m really excited to be doing events in three different cities in Wisconsin today before heading to North Carolina and Virginia tomorrow.”

Asked about the $1 million donation from the Qatari government to the Clinton Foundation, which the Foundation confirmed last week, Kaine said it did not violate Clinton’s agreement with the State Department because Qatar was already a donor before Clinton entered the State Department.

“The government of Qatar had been a donor to the Foundation, which as you know does great work around the world, before she became secretary of State,” Kaine said. “The fact that they are a donor has been known but they were a donor before Hillary became secretary of State, this wasn’t a change in their position.”

The vice presidential candidate, a senator from Virginia, said Clinton is the “underdog” in the race because she’s trying to do something historic -- and said that, when he encouraged her to run back in 2014, he told her the same thing.

“I said no matter what the polls say and no matter what you see in an editorial, consider yourself the underdog, you’re trying to do something that’s never been done,” he said. “If it had been easy for a woman to be president of this country, we would would have had a woman president of the country -- so consider yourself the underdog until they call you the winner.”