请问句中的in effect干什么成分

Attorney Goodmans charge was answered in prefatory remarks again by Congressman Henry Hide of Illinois, a member of the House, in effect acting for the prosecution.

in effect：事实上

in effect

—used to say that one thing has the same effect or result as something else

The suggestion wasin effectan order.

你的句子中in effect 大约等于actually, 修饰acting for目前分词短语，该分词短语为Congressman Henry Hide of Illinois的后置定语。