The only real business explanation is one that Ben Shapiro puts forward: Nike is trolling Trump and conservatives to create a bunch of free publicity (yes, I get the irony) and increase sales, particularly to blacks who buy Nikes at a much higher percentage than whites — but still smaller raw numbers.
They also steal them in much higher percentages
Trust me on this, this was a well thought out, carefully conceived and intentional move aimed towards a single objective: to increase sales.
Now, please note I use sales in the total sense ie world-wide, global, not just the US market. We don't have access to Nike's internal numbers, but the research and analysis behind behind this move certainly can be measured in many, many $ millions. That includes regional demographics studies, growth expectations, (disposable) income estimates, etc. It also includes careful pysch research into potential customer segments with respect to how they feel towards perceived 'injustice' and the desire to 'make a statement' through product identification.
We won't know if their attempt will be successful; but that's why they run horse races. Don't be surprised if this results in increased overseas sales - reflected in Nike's share price. That being said, it could also be a mistake - nothing is guaranteed. They know full well how pissed off certain segments within the US market ie FReeper types, will be. It's all part of the calculation; but to suggest this is some kind of misguided misreading or being out-of-touch is nothing more than an exhibition of ignorance (or wishful thinking).