There is already an option for a minimum TL in order for members to create polls, but no option to limit who can vote.
We experienced a situation where a bunch of accounts were created, each with 1m read time, who voted in a poll and did nothing more on the site.
It would therefore be cool if polls could only be voted in for members with some minimum TL e.g. TL1.
Current when trying to vote in a poll if not logged in, the login box is shown. This would need a new dialog to say something like “Sorry, polls are only available for voting by TLx members.”