The video purports to show an undercover Project Veritas journalist recording the campaign staffers discussing how during voter registration drives they openly endorsed Clinton and the Democratic Party. That’s an apparent violation of election law, which prohibits registration workers from advocating for a candidate or a party.
http://dailycaller.com/2015/09/10/james-okeefe-releases-his-most-damning-clinton-campaign-sting-video-yet-video/