third rail

US /ˌθɜːrd ˈreɪl/
UK /ˌθɜːrd ˈreɪl/
"third rail" picture
1.

第三軌, 敏感問題

a political issue that is so controversial that any politician who dares to broach the topic will suffer a backlash from voters

:
Healthcare reform has become a third rail issue in American politics.
醫療改革已成為美國政治中的一個第三軌問題。
No politician wants to touch the third rail of social security.
沒有政客願意觸碰社會保障的第三軌