I think there's a noticeable undercurrent of the West as the place where the bad things of colonialism/Old World society cannot yet reach. If you focus on that, you can begin to minimize some of the genre's pernicious effects. So you have PCs in the region avoiding those who would oppress them back East, as well as those who infringe on the freedom the PCs have. There is room for a former slave, an outlaw fleeing injustice, and a native whose home is threatened. But the frontier is always moving, and it gets inexorably easier for the oppressors to get across it.