It's often the case that opinions are judged depending not on their content, but by whether one likes or dislikes the people who express them.
ご質問ありがとうございます。
"It's often the case"＝「それはよくあることで」
"that opinions are judged"=「意見は判断される」
"depending not on their content"＝「内容によってではなく」
"but by whether one likes or dislikes the people who express them."＝「（意見を）表現する人達を好きか、嫌いかによって。」
ご参考に！
アメリカ合衆国 
