Using your position to influence the election

There was a professor DT who was running for city council and he found out that one of his students was the HR director for a company and the son of his main rival was an employee for her company. So when the student turned in her assignment he gave her a zero. Then he called her up and said he would give her an A if she announced that the employee was being investigated for sexual harassment. She refused but someone in the next cubicle overheard the whole thing and reported it to the school administrators. What action should they take?