– Republican vice presidential nominee Sen. JD Vance didn’t let a power outage derail his preparations for Tuesday’s debate with Minnesota Gov. Tim Walz, the Democratic Party’s running mate.

A source familiar with the senator’s debate prep tells Fox News Digital that over the last month, former President Trump’s running mate took part in a series of murder board sessions with his team.

For those not familiar with the term, a murder board is a group of people who ask tough questions and have candid discussions to help someone prepare for a difficult examination or test, or in Vance’s case, a vice presidential debate.

According to the source, Vance conducted a mock debate over the past week, with Rep. Tom Emmer of Minnesota, the House majority whip, playing the role of Walz, Vice President Kamala Harris’ running mate. Former Trump administration Treasury Department assistant secretary Monica Crowley played the role of one of the moderators from CBS News, which is hosting the debate in New York City.

Halfway through the mock debate, the power went out, as a strong storm slammed through the vicinity of Cincinnati, Ohio, where Vance lives and where the prep session was held. But according to the source, who shared the details first with Fox News, Vance and the team continued on, using lanterns for lighting and cellphones for timers.

Emmer, who steered the House Republicans’ campaign committee in the 2020 and 2022 cycles, said last week in a Fox News Digital interview that ‘it’s an honor to be asked to play a very small part in helping JD and President Trump expose the failures of Kamala Harris and Tim Walz.’

Emmer and Walz overlapped for four years in the House before Walz won election in 2018 as Minnesota’s governor. ‘I do know him probably as well or better than most on the Republican side,’ he said.

And Emmer, taking a shot at his fellow Minnesotan, argued ‘the hardest part of playing Walz… is trying to tell lies with a straight face, because that’s what he does. He’s good at the debate game, but there isn’t substance there. There’s a lot of air.’

Former President Trump, asked Monday if he’s given his running mate any advice, told reporters, ‘No, he doesn’t need it.’

But he added that he and Vance have ‘been speaking a little bit back and forth’ and that he thought the senator was in ‘good shape.’

Part of the Trump campaign’s strategy ahead of the debate is to raise expectations for Walz.

‘Walz is very good in debates. I want to repeat that. Tim Walz is very good in debates. Really good. He’s been a politician for nearly 20 years. He’ll be very well prepared for tomorrow night,’ Trump campaign senior adviser Jason Miller told reporters on Monday.

Vance, his family, and top aides and advisers arrived in New York City on the eve of the debate.

Fox News confirmed that Vance will speak to a conference of major Republican donors Monday evening in Manhattan.

According to a source familiar with the GOP vice presidential nominee’s plans, Vance will address the American Opportunity Alliance behind closed doors. That’s a network of major GOP contributors that includes billionaire investors/mega donors such as Paul Singer, Ken Griffin and Warren Stephens. The development was first reported by the New York Times.