a person who likes to be politically independent and does not support or remain loyal to any political group

As a reporter, I've met with political groups large and small, Democratic and Republican, Green Party, mugwumps, you name it. 作为记者，我见过大大小小的政治团体，民主党的、共和党的、绿党的、超然派的，应有尽有。

a stupid person

To make a fresh milk cheese at home is the simplest of processes; any mugwump can do it. 在家里用新鲜牛奶做奶酪再简单不过了，什么笨蛋都能做到。