In August 2018, the Democratic National Committee voted to disallow superdelegates from voting on the first ballot of the nominating process, beginning with the 2020 election. This required a candidate to win a majority of pledged delegates from the assorted primary elections in order to win the party's nomination. The last time this did not occur was the nomination of Adlai Stevenson II at the 1952 Democratic National Convention. Meanwhile, six states used ranked-choice voting in the primaries: Alaska, Hawaii, Kansas, and Wyoming for all voters; and Iowa and Nevada for absentee voters.