JD Vance's Secret Service codename revealed: Running mate's 'Hillbilly' roots and love of football inspired call sign. But could it cost Trump?

A lot changed for Sen. J.D. Vance after being selected last week as Donald Trump's running mate.

Within days he had his own campaign plane and a Secret Service codename.

The longtime Ohio State football fan is now known to the agents protecting him as 'Bobcat,' after the team's nickname, DailyMail.com can reveal. 

'Anyone who knows JD is not surprised by his choice of Bobcat given his longstanding love of Ohio State football,' said a longtime friend.

It means he joins 'Mogul' (Trump) on a ticket looking to upend the plans of 'Celtic' (Joe Biden) and beat Pioneer (Kamala Harris) on Election Day. 

Once upon a time, the codenames were essential to security. But with sensitive  communications now encrypted, they are used now largely for brevity and clarity.

Candidates get to pick from a list, which means they can choose codenames that mean something personal  to them.

Mike Pence, for example, made the most of his Indiana roots and was 'Hoosier' for his four years as vice president.

Vance, 39, installed as Trump's running mate at the party convention last week, has taken similar inspiration.

He is a lifelong football fan and writes movingly in his memoir 'Hillbilly Elegy' about bonding with his unreliable, addict mother over players and tactics.

And after serving in the Marines, he enrolled at Ohio State University to study political science and philosophy.

His blue-collar Buckeye credentials are one of the factors that propelled him on to Trump's V.P. shortlist. 

Vance could be the key to winning over states in the so-called blue wall, such as Pennsylvania and Michigan. But could there be a problem with his Ohio State Bobcats codename?

Michigan is after all home to Ohio State's biggest rivals in the form of the University of Michigan.

'My name is J.D. Vance, from the great state of Ohio,' he announced proudly as he accepted the V.P. nomination in Milwaukee last week. 

His words fueled huge cheers from the Ohio delegation, who struck up an 'O-H-IO' chant. Vance joined in before realizing there was an election to win. 

'You guys, we've got to chill with the Ohio love,' he said with a smile. 'We've got to win Michigan too here.'

It happened again later in the speech when he brought up his time at Ohio State.

The Michigan delegation erupted in its own goodnatured 'Let's Go Blue' chants.