Minnesota Gov. and Democratic vice presidential candidate Tim Walz is constantly worried he will let Vice President Kamala Harris down and blow his debate this week against Ohio Sen. JD Vance, according to a dozen campaign officials who spoke to CNN.

The network reported that Walz — a veteran politician with 12 years in the U.S. House of Representatives and five years in the governor’s office — warned his vice president last month that he was a “bad debater.”

“He’s a strong person,” Minnesota Sen. Amy Klobuchar, who has known Walz for 18 years, told CNN. “He’s just not a lawyer-debating type. It’s not like he dreamed of debate in first grade.”

When he takes part in Tuesday’s vice presidential debate on CBS, he will face off against Vance, a veteran debater who, like his running mate, Donald Trump, is not afraid to distort the truth – such as his false claims about migrants in Ohio by using the pets of Eating people – or firing aggressive broadsides at political enemies.

Vance was by far the most open and accessible to the media of the four candidates from the two major parties and, as one of Trump’s most aggressive surrogates, regularly duked it out with journalists.

CNN reported that Walz feels “real contempt” for Vance, who he says has abandoned his shared working-class roots with his high-profile adventures working for billionaire venture capitalist Peter Thiel.

But sources who know the Minnesota governor told the media that Walz’s frequent clashes with his opponent on the Republican ticket for a move to Yale were partly due to his “fear that his opponent there had learned to debate sharply “.

Walz, who won a House seat with few major media outlets by prevailing locally and was a strong broker to get Harris into the House, does not share Vance’s sharp oratorical skills and has instead been portrayed as a lovable everyman on the campaign trail.

CNN reported that it was apparently Harris herself who came up with the idea of ​​calling the former high school football coach “Coach Walz.”

“The guy is regaining the old white guy masculinity, away from the toxicity,” a source told CNN.

To prepare Walz for Vance, his aides had him sit through mock debates with Transportation Secretary Pete Buttigieg, considered one of the Democratic Party’s most formidable surrogates. One tactic they have used to prepare him, according to CNN, is to ignore Vance and attack Trump, hoping to get the temperamental Republican candidate to lash out online or in the days after the debate.

The hope is that this will be enough to prevent Vance from potentially dismantling Walz’s dazzling personality through a tenacious and effective performance.

“People are assuming that this is a permit for white male hunters in the countryside,” a Democratic campaign aide told CNN. “Yes, for the 1 or 2 points of those we want to move. But it goes much deeper than that: It is a walking permission structure that allows people to feel joyful and hopeful about themselves.”