Why is there a proposition and why is it "in" in THIS sentence? Why is "be" used other than "should be"? What's the structure of the that-clause?
"Moulton’s letter cited the concerns of others in asking that the centers be shut down."
I met the sentence when reading "Moulton wants local colleges to cut ties with Chinese institute"(https://www.bostonglobe.com/metro/2018/03/09/moulton-wants-local-colleges-cut-ties-with-chinese-institute/2l5Y9Oa1WgG3SuapqGCaNP/story.html?event=event25?event=event25)