Character assassination: a vicious personal verbal attack especially one intended to destroy or damage a public figure's reputation.

诽谤：恶意的人身言语攻击，尤指意在破坏或玷污某位公众人物声誉的诽谤。

youdao

These tax cuts became law, the business ones in 1962 and the personal ones early in 1964, a few months after the assassination.

FORBES: Trashing JFK's Tax Cuts, One of the Greatest Policy Successes of All Time