gadflies
n. 牛虻( gadfly的名词复数 )
If you refer to someone as a gadfly, you believe that they deliberately annoy or challenge other people, especially people in authority.
It still remains to be seen whether Buchanan will be just a gadfly or a real threat to the president.
布坎南只是故意搅局还是对总统构成真正的威胁,这还有待观察。