Calgary, Canada's "most conservative city" has a Muslim mayor. A Republican would need to win Calgary to win Alberta, and I can't picture a Muslim getting elected in the US anywhere a Republican would win.
Re winning Calgary: not necessarily, esp. if the GOP gets huge compensating rural pluralities elsewhere in the province--or, for that matter, if a Jason Kenney had some multicult-friendly influence on GOP strategizing.
And the first Muslim in congress, Keith Ellison of Minnesota, was first elected in 2006--the same year that Tim Pawlenty was reelected governor, and two years before Norm Coleman was *nearly* reelected Senator.