I tried to get the vox populi badge a couple of times.
The system didn't allow me to go over 32/40 votes. Since 40 votes are needed for the badge, it is impossible.
Is that a bug, or am I missing something?
The daily vote limit is a little counter-intuitive.
Each day you get 30 votes, plus 10 votes that can be used only on questions. However, you can't just save those votes for the end, because of the way the extra votes were added into the system. Once you get the "5 votes remaining" message, your daily vote limit has been set.
So, suppose you cast 25 votes on answers and then get the 5-vote warning. You're only getting 30 votes that day. In your case, I'm guessing you voted on two questions and 25 answers, got the 5-vote warning, and ended up with 32 votes.
If you're aiming for this badge, the safest thing to do is to vote for 10 questions before you reach 30 votes for the day. After that, you should be able to vote for any mix of questions and answers and get 40 votes total.
Further information: MSE FAQ entry on votes.
You should not vote to vote. That devalues the voting system.
Just vote on what you would vote on, and if you get a badge for that, you get a badge for that. And if not, not. But please don't go hunting for stuff to vote on, just to get a badge. That makes me not want any of that repuation.
I was wondering about this too -- I tried to vote all 40 times -- I got the 30-vote-badge (suffragist) , and thought maybe one had to earn that before earning the 40-vote one.
I figured since I'm relatively new, I'm not just hunting for the sake of hunting --the old questions are still NewToMe! And older Qs are often still relevant. (I got an "archeologist" badge for answering something pretty old in UX -- I was just looking for any accessibility questions I could learn from.)
I'm also seeing if older questions inspire new questions, for our question drive.
So now I know to be sure I upvote Qs as much as As, and earlier, too. (SE has lots of weird quirks.)