It's taken two years of sometimes ugly public fighting, but Democratic Party leaders have now acted to limit their own high-profile roles in choosing presidential nominees. The decision gives even more weight to the outcome of state primaries and caucuses.

The Democratic National Committee has overwhelmingly approved the changes at the party's summer meeting in Chicago.

At issue are party insiders known as superdelegates. They're the hundreds of DNC members, elected officials and party elders who attend presidential conventions as automatic delegates.

In 2020, that group won't be able to vote on a contested first presidential ballot at the party convention. They would still have votes if the nomination takes multiple rounds of voting.

The changes come after two years of negotiations stemming from the bitter nominating fight in 2016 between Bernie Sanders and Hillary Clinton.