Hillary Clinton is reportedly set to announce a constitutional amendment designed to overturn the "Citizens United" Supreme Court decision that removed many barriers to political spending.

Throughout the Democratic primary, Clinton echoed calls from her progressive rival Bernie Sanders to implement strict campaign finance reform measures that would cut down on corporate donations to political action committees. Her announcement Saturday at the annual Netroots Nation conference will cement her support for proposals she first floated during her race against Sanders.

Although outside spending groups have raised more than $84 million for her this cycle, according to the Center for Responsive Politics, Clinton has become a vocal critic of the Citizens United decision and the so-called "dark money" it allowed into the political system. By comparison, outside groups working on behalf of her Republican rival, Donald Trump, have raised a little more than $3 million.