I would argue they were just misogynist critiques not racist. Every first lady in my living memory has been caricatured and insulted by the opposing party's supporters, as well as the children. If she's not attractive she gets insulted for not being attractive. If she is attractive she is called a bimbo or worst. This is just part of the same tired democratic fantasy to paint their opponents in a broad stroke as racist because they don't want to think it is an extraordinary circumstance.