No I realise that. I'm just testing whether that statement could ever be generally true and it looks like it can't.

The best we could argue would be, if you vote you're taking part in the political process.

Because the hypothetical jury doesn't prove that you support the outcome or even the overall process.

There's a name for this type of argument but I'm struggling to remember the name. It's a good one though. 

 I think I see what you're saying, but couldn't you make the same case you made for the jury (technically a part of politics) for a political process (I'm assuming you mean an election)? 

 I was thinking of the electoral process, yes. It would take a lot of effort to test the whole democratic process. I like to distil arguments into simpler contexts to make sure they work :) 

 That's why reposted to reword. I tried to go simpler. Thanks for the discussion.

My original note wasn't particular to the electoral process. 

 Thanks for pointing me back to the revised post. I can't see much wrong with that statement :)