(政治上)独自の立場をとる人、「一匹狼」
1.a person who is unable to make up his or her mind on an issue, especially in politics; a person who is neutral on a controversial issue.
2.a Republican who refused to support the party nominee, James G. Blaine, in the presidential campaign of 1884.
Citations formugwump
I was very anxious to keep him in his place, but at first I could not think of any way to help him, for I was a mugwump. We, the mugwumps, a little company made up of the unenslaved of both parties, the very best men to be found in the two great parties--that was our idea of it--voted sixty thousand strong for Mr. Cleveland in New York and elected him.