Who cares. Corporations can do what they want with their money regarding politics.
I think conservatives/republicans should care, no? Corporations provide some funding and other services for the convention. Less donations/services from them means the GOP has to fill the gap some other way, potentially taking away resources they could have used elsewhere.
In 2004 the NYC convention ran out of money and Bloomy had to personably bailout the GOP presumably for some sort of favour. I guess the GOP could find some other megalomaniacal NYC based billionaire seeking to make a deal?
