Looking at this map
You can see the drop off in percentage of Mormons as you move east, I guess where to put the “border” of where you might expect to find Mormon politicians is debatable.
I didn’t know there were LDS offshoots, other than the “fundamentalist” sects (nothing more than a smattering of cults and independent Mormons that aren’t officially organized) that still practice polygamy.
Fair enough. Both OKC and SW MO are areas where Mormons are a small minority, and thus it is unusual that a Mormon would be elected to Congress. I just can’t bring myself to call them “Eastern” states. Heck, I’m still partial to calling Pittsburgh, Cleveland, Detroit and Cincinnati “Western cities,” as they certainly were deemed to be by the National League and the American League during the first half of the 20th Century (each league had 4 “Eastern teams” and 4 “Western teams,” and a “Western road trip” would take you to Pittsburgh, Cincinnati, Chicago and St. Louis in the NL and Cleveland, Detroit, Chicago and St. Louis in the AL).