So the question isn't whether this hurts brand perception in general (some evidence it has), but whether it hurts or helps them with the more ignorant and anti-American that their customer base skews towards. And since blacks are over-represented in the NFL contracts and in buying overpriced sneakers, maybe this will work out for Nike in the long run? Even if their brand is coupled to ignorant opportunism for everyone else. I mean does anyone really believe they care about social justice, or that they're just using it to sell shoes?
It was a silly meme, as Kaep didn't sacrifice anything, and the cause was flawed at it's premise. And of course no one had a problem with him protesting on his own time or off screen -- the problem with was by forcing fans to pay to watch an idiot insult them over things he didn't understand.
The first day, their stock lost a few billion dollars (≈3%) in stockholder value. So the investors didn't like it in the short term.
Iran's Ahmadinejad supports Kaep (and anything anti-American), by hinting at what a racist country America is, because one of our top quarterbacks not having a contract. (He seems to agree with Democrats, BLM, and Nike). Of course, everything about that is wrong -- Kaepernick had the worst record for 2 years before he became a pain-in-the-ass and was dropped. In Iran he would have been tortured or killed for questioning the regime. And if he was really good, he probably would have been fine.
They're setting themselves up for failure -- as to the Social Justice Warriors, too much is never enough. And on queue, and few SJW's came out complaining that Nike has no credibility to hijack Kaep's message. 
- General polls not looking good, but I want targeted customer polls, including globally: https://www.cbsnews.com/news/nike-colin-kaepernick-ad-is-hurting-its-brand-poll-suggests/?ftag=CNM-00-10aab7e&linkId=56515845