But that's the point, isn't it? We want to know which characters are the most popular. We don't need to know which characters are the least. And Project M isn't likely to add in 5 characters at once, they'll likely add 1, maybe 2 at the most. And with that new information, everyone should be considering how that impacts who they want next.
For instance, say Bowser Jr gets in next, how many people do you think will finally admit that, "Okay, we're good on Mario reps, don't need any more." And thus wouldn't vote for Toad or Waluigi.
Or say we actually get Ridley (though I still very much doubt this), would you still want Dark Samus? Or since Ridley is likely to be a slow moving character are you going to want another slow moving character after that? Maybe not. So maybe you don't want to vote for King K Rool anymore.
I mean, even a poll that let you vote more than once would be fine, but half votes and anti-votes is silly. Stick with the tried and true methods.