Back in the olden days, companies like Nike would buy ads on TV and in magazines. From Spike Lee to Bo Knows, these ads would make or break sales for the company. All that was needed for the ad campaign to be successful was enough TV time and magazine space and a smart, catchy or funny ad.
Now, ads in traditional media do not do anything. Fewer and fewer people watch network TV and read print media. Everyone advertisers want to influence is on social media now. But ads on social media do not work because of ad blocker and the fact that people are generally oblivious to banner ads and sponsored posts on social media. So, now the way to get a big advertising push is to go viral on social media. It is all anyone in advertising talks about these days. Nike very adroitly has exploited the tension over the national anthem at the start of the NFL season with its CK ad campaign and is trying to keep it going with a pro LGBT campaign based on Caster Semenya. I have never seen the CK ad campaign anywhere other than in the news and on social media. So, the campaign is a huge success.
The hottest thing in the shoe market right now is "athleisure". Nike is gunning for this market in a big way. This market is predominantly young, single and urban. This market is not looking for shoes that go well with a red Make America GA hat. The market for functional athletic footwear is largely stagnant. The marathon boom is over. Other fitness fads (crossfit, yoga, HIIT, spinning, etc) are not dependent on any specific footwear. Participation in sports like tennis and golf are waning in the US. So, any loss of market share due to political preferences is going to be minimal for Nike.
And if Nike's main market was for orthopedic shoes for men in their 60s, they would have ads with Sean Hannity and Tim Tebow. Nike is purely a profit machine and does not care at all about politics.