Cite one law, one decree, one writ, one statute, one openly expressed opinion...that Ulfric or the Stormcloaks express or directly support...that persecutes or harasses the Dunmer or the Argonians.
The most xenophobic and racist faction in Skyrim is the Thalmor. The Empire actively "cooperates" with the Thalmor; it aids and abets Thalmor activities against Skyrim citizens. Or looks the other way...which functionally is the same thing.
The Khajits are not allowed in any city in Skyrim, Imperial or otherwise.
The grey quarter in Windhelm is 150 years old. It is not Ulfric's doing. He "inherited the economy".
The Lore says the Dunmer are "clannish" and "distrustful" of others.
Are there racist in Skyrim? Yes, there are. Not all of them are Stormcloaks.
Are there racists in the Stormcloaks? Yes, there are. But Ulfric is not among them.
Whichever side you choose, you will be among racists and esp. as an Imperial, cooperating with Skyrim's most racist people....furthering their racist agenda.
So...if it's guilt by association, no matter which side the Dragonborn chooses it's racist.