Can a visitor vote in polls more than once?

[Moonbaseone]

Hi. I am just wondering, are visitors and members allowed to vote more than once in polls? I use polls to let everyone pick which cartoon they want me to add to the site next. Once I add it, I reset the results, and edit the winning cartoon with a new one.

I am curious, if I just redit the poll, will the members/visitors still be able to cast a vote, even though they already have? Or, shoul dI just delete the poll and add a new one?

Thanks.