ESPN has the right to be who they are and hire/fire at will. That said, your comparison of the Dixie Chix is totally wrong. The 'Chix' were blasted all over the news, on magazine covers, and tried to be promoted as hard as they ever have been.
What happened is that the 'Chix' audience predominately leaned "conservative" which made TV exects uncomfortable, not the what the 'Chix' said. Totalitarians hailed the 'Chix' but their audience turned their back on them which meant potential lower ratings, lower sales and nervous advertisers. In ESPN's case, there ideology quickly canned Williams, Jr, not the audience. Heck, most of the football audience probably agreed with the analogy Jr. made.
Is Hank Jr. going to get the "cover" treatment?
Are Time Magazine or another mainstream rag going to offer Hank Jr. a sympathetic spin?
The 'Chix' were blasted all over the news, on magazine covers, and tried to be promoted as hard as they ever have been. I get what you're saying about the Dixie Chicks being trumpeted and praised in the media... my point was directed at the loss of CD sales and fan reaction (at which I was quite pleased to see!). They never reached anywhere near their high point again.
As for ESPN's ideology, my point was Williams might've been wise to take that into account before the analogy to Hitler. But hindsight = 20/20.