A personal attack (ad hominem) — attacking someone's character, background, or person rather than addressing the argument or issue.
SNS上の人身攻撃がエスカレートして、建設的な議論ができなくなった。
Personal attacks on social media escalated and constructive discussion became impossible.
反論するなら論点に沿って指摘すべきで、人身攻撃は避けるべきだ。
If you want to counter an argument, point out issues with the argument — avoid personal attacks.
政治討論で相手の過去だけを取り上げるのは明らかに人身攻撃だ。
Picking only at an opponent's past in political debates is clearly a personal attack.