Susan Lerner is one of the city's leading experts on ranked-choice voting. As Executive Director of the nonprofit Common Cause, she was instrumental in the campaign during New York City ballot initiative to bring ranked-choice voting to New York City primaries and special elections. That measure goes into effect in 2021. But while an overwhelming majority of New Yorkers voted in favor of the change - there's still a lot of confusion about what it is, how it will work - and who stands to benefit.