Tom runs for class president, but that's only because Jessica has nominated him. If it had been left up to him, he wouldn't have put his name forward. In fact, when Jessica nominates Tom his initial reaction is one of utter horror:
It was as if I’d suddenly been zapped with a thousand volts of electricity. A hundred thousand. Every part of me felt a jolt of hot energy.
A naturally shy, withdrawn young man, Tom is terrified at the prospect at running for class president. And he really couldn't be more explicit about not wanting to be class president if he tried:
I’m no candidate. I didn’t even show anyone my poster. I didn’t even want to be president...
But it's too late. Jessica has nominated Tom and so Mrs. Tracy writes his name on the board with the other candidates. Tom's stomach's churning; he's feeling cold; but he tries to deal with his feelings by plucking up the courage to nominate Jessica for class president. As well as getting her more involved in class business, nominating Jessica will also take some of the heat off Tom. And it works. Instead of looking at him, everyone's now either looking at the board or at Jessica.
In the ensuing contest, Courtney is the winner, with seven votes. Tom receives just one vote, which in some ways is kind of a relief as he'd never wanted to be class president in the first place. At the same time, finishing last makes Tom feel even more of a loser than usual, which is really saying something.
However, it's not all bad news, as later that evening Tom receives a call from Jessica inviting him over to her house.