英语长句分析

英语长句分析
The filibuster,a parliamentary device that slows the snail's pace that prevails even in the best of times in the congressional session and test the endurance of everyone associated with it,seems more and more an anachronism in the age of telecommunications.
parliamentary device that slows the snail's pace that prevails even in the best of times in the congressional session
那个snail's pace 后面跟的that从句式修饰snail's pace的?翻译起来感觉很怪啊
我的意思是 snail's pace 后面这句 that prevails even in the best of times in the congressional session and test the endurance of everyone associated with it
是修饰snail's pace的？