Arizona’s senators had been watched in past years when Republicans John McCain and Jon Kyl wielded outsized clout in the chamber because of their seniority and because of Kyl's status as a GOP leader.Now, in a closely divided Senate, Sinema and Kelly’s centrism could position them as power players despite their relative newness. "They are right in the middle of the fulcrum in the Senate," said Larry Sabato, the director of UVA’s Center for Politics.