In a democratic society, in the end might makes right. So if 70% of the population want to apply boycotts or cancel culture to 15%, the only protection the 15%

In a democratic society, in the end might makes right. So if 70% of the population want to apply boycotts or cancel culture to 15%, the only protection the 15% will get is whatever is afforded them by constitutional norms that the courts choose to enforce. If it's more like 40% trying to cancel a different 40% then it's more like a cold civil war than like democracy. The Harpers' letter tells me it's not even 40% pushing cancel culture, but maybe more like 15% trying to cancel some 40%. Once the folks in the middle feel threatened enough to make cause with the targets, the 15% will have to back off.