I flew on Air Midwest (USAirways regional) and Midwest Express, both out of KMCI, and didn't have a problem with either of them. Also went through security at KMKE without problem as well. I think the only type of razors that are strictly prohibited are straight razors, but like xrjpilot said, everyone might have a slightly different policy that is subject to change.
Oh, I had both a Mach 3 razor and shaving cream in my carry-on bag for all of these flights.