A law like this would in turn be unconstitutional, as it would violate the advertisers freedom to "associate" with whom he/she wishes. If an advertiser does not want his/her product associated with a blathering liberal, it is their choice not to advertise on that program.
Likewise, if a particuular institution does not want their good name tarnished by the acts of one or a few radicals whose ideologies differ, then the institution is free to dis-associate themselves. It's their right.
Any "laws" to the contrary would in effect "force" people to associate with those with whom they disagree.