What a shifty arguer he is, refusing ever to give a straight answer to a straight question.

他真是一个狡猾的辩手，一直拒绝对一个直接的问题给予直截了当的回答。

《柯林斯英汉双解大词典》

Often, the arguer never returns to the original issue.

通常论者不会再回到原来的问题。

youdao

In summary, the arguer fails to convince with the argument as presented.

总而言之，论述者没能用其提出的论据来说服我们。

youdao

But other studies suggest that groups which discuss the job at hand may be too swayed by the alpha arguer among them.

ECONOMIST: Central banking