Story highlights Superdelegates were a key sticking point during the Democratic primary process last year

The DNC formed a "unity" commission to study the issue

Washington (CNN) The Democratic drama over superdelegates is back.

A "unity reform commission" the party created last July -- made up of leaders selected separately by Hillary Clinton and Bernie Sanders -- is tasked with making a recommendation by the end of this year: Keep superdelegates, eliminate them, or something in between.

But the 21 members of the commission admit that almost a year after the Clinton vs. Sanders nominating fight ended, the bitter feelings still haven't gone away.

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"I think tensions will definitely start to rise as we get into the nitty-gritty of proposals," said Jane Kleeb, the Nebraska Democratic chairwoman and a Sanders selection for the unity commission.

"But I'm confident -- and I guess hoping, at the same time -- that it's not just, 'Oh, you're a Bernie delegate, so of course you think that way,'" added Kleeb, who rose to national prominence as an activist against the Keystone XL pipeline.

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