Democratic presidential candidate Bernie Sanders has picked up his first Wisconsin superdelegate: state Rep. David Bowen of Milwaukee.

"It was hard to ignore the huge numbers of Democrats in our state that have decided and that are invested into the Bernie Sanders platform," Bowen said on Thursday.

Superdelegates are only involved in the Democratic presidential nomination process. They are typically former elected officials or high-ranking party members. Superdelegates are different from traditional delegates because they can choose to support whomever they want, regardless of the popular vote in their state.

Bowen said he hopes his pledge for the Vermont senator shows Sanders supporters in Wisconsin that their voice is being heard.

"There was a clear winner on Tuesday," he said. "I wanted to congratulate the Sanders campaign and let their supporters know that I support their decision to pick the platform of the political revolution."

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Sanders defeated Hillary Clinton in Wisconsin’s presidential primary on Tuesday, with 57 percent of the vote to her 43 percent.

Six other Wisconsin superdelegates have pledged their support, all favoring Clinton.

Three delegates remain uncommitted: state Democratic Party chair Martha Laning, U.S. Rep Mark Pocan and Democratic National Committee member Jason Rae.

Pocan told reporters last week that he will not pledge his support until after the final presidential primary in June, with an eye toward uniting the party behind a single candidate.