Only that the law isn't on your side. Sam Young was almost certainly an employee "at will" which means that either party (the employer and the employee) could sever the employment relationship at any time for any reason. Sam could quit the job whenever he wanted and the grocery store could fire him whenever he wanted, as long as they didn't do so for a specifically prohibited reason, such as because of his age, race, religion, national origin, etc. So they could legally fire him for wearing a Green Bay Packer jersey to work if they wanted to. (Since I'm in Wisconsin however, I applaud Sam's sartorial choice. Who in their right mind would wear a nasty Cowboy's jersey???)
The other argument you may be thinking of making is that wearing a GBP jersey is protected by the First Amendment to the Constitution which guarantees us the freedom of expression. Unfortunately for Sam, that allows him to criticize the government and doesn't apply in the workplace.
I have to tell you, amoore, you've been handed the losing side of the case. I don't see any legal basis on which you can argue that the employer acted unlawfully in terminating Sam.
You can certainly TRY to argue that it's a First Amendment issue and/or that term'ing Sam was a "public policy" violation. The latter means that while there was no specific law that the employer violated, the public's best interests were harmed when the employer terminated Sam for this reason.
Your best bet however may be to argue for a change of venue for the trial and see if you can get it moved to Wisconsin. You'll have a much more sympathetic jury here.
Good luck.
