Legal questions can often be split into two parts: whether you can do something, and whether you should. And the answers to those aren't always the same.
Such is the case with the latest blip in pseudo-political outrage over Nike making former NFL quarterback Colin Kaepernick the face of its latest "Just Do It" campaign. The move angered many (although apparently not its customers or investors), causing some to mutilate or burn already purchased Nike apparel and even led to rumors of businesses banning employees from wearing Nike at work. So, can you ban your employees from wearing Nike? And should you?
Dress Codes and Can Yous
Employers are generally given a considerable amount of discretion in setting and enforcing dress codes, so long as the dress code isn't discriminatory or based on gender, race, or religion. So, a company-wide no-Nike policy could be legal. However, some states (like California) are particularly protective of political speech at work. And, in this case, it's hard to divorce a Nike ban from its political underpinnings.
The reason Nike's association with Kaepernick is in any way controversial is that the former QB claims he's has blackballed from the league after kneeling during the national anthem before games to protest race-based police brutality and inequalities in the criminal justice system. Those protests were mischaracterized by many as anti-flag or anti-troop, and garnered the scorn of President Trump. Therefore, an employee donning Nike gear at work could feasibly argue that they are doing it for political reasons, and, if you're in a state that offers legal protections for employees based on their political expressions, a Nike ban could get you into trouble.
Shoes, the Swoosh, and Should Yous
"[W]hat signal does this policy send to your employees? Do you want Stepford employees? Do you want a homogeneous workforce where everyone thinks and acts and dresses the same, and is punished for expressing themselves differently? It's one thing to have a personal appearance policy (no offensive clothing, neat appearance, etc.), but another to ban a company's products because you, as an employer, disagree with its choice of spokespeople. It's certainly not a workplace at which I would want to work."
If your goal is to keep your small business running smoothly and avoid political conflict in the office, focusing on your employees' productivity, rather than their choice in footwear, seems like the way to go.
And before you institute any dress code, you might want to talk to an experienced employment attorney to avoid any legal ramifications.