You either allow Political Speech at work or you don’t.
Give all the Employees Uniforms and move on. It isn’t Rocket Science.
I have always noticed how the European Auto Makers Employees wear Uniforms while the American Auto Makers UAW Employees look like they are hanging out at a Backyard Barbecue.
Detroit is too cheap to issue uniforms. Or do things like “make sure our ignition switches work” or “maybe our brake system shouldn’t set the truck on fire.”