Re: What's the concern?
"For our non-US readers, this database won't contain anyone's voting record. That information is not stored on anyone, since ballots are secret. The party affiliation field in there would be populated with what party you registered under. You aren't required to register with a particular party (you can choose 'independent') and you don't have to vote your registered party, with the exception of some states where you can only participate in a particular party's primary/caucus if you are registered with that party."
"For my part I chose a party I'm registered under because I found when you register independent BOTH parties call you up and try to get you to vote (and they treat registering under a third party as independent) So it is better to choose one just to cut by half the number of annoying calls you may receive during election season."
That nuance might be obvious to many, but it may not be so to a crazed dictator. Misinterpretation of the purpose of a table field is one of the scourges of database design.