Ask HN: With N numbers, determine if a tie is possible?

So I was thinking about the election and I was wondering if you had N numbers, what type of algorithm would best be able to tell you if a tie is possible? I know that the sum being divisible by an even number doesn't necessarily mean there is a way to tie. This was inspired by thinking of the up coming election. You can assume all numbers in N are positive and that there may be numbers repeated, think electoral college as an example.