Mutts and purebreds

Do dog shows welcome mixed breed dogs to enter the same way that the purebreds can?

Or are the mutts put off into "separate but almost equal" shows, where, provided that the mutts and the mixes have been surgically spayed/ castrated, the mutts and mixes can perform, but not enter into shows for breeding dogs?

For me, it is not hard to figure out why some people see a connection between racist social ideas, and purebred dog breeders.