WASHINGTON — Democrat Hillary Clinton will call for a constitutional amendment to overturn the Supreme Court’s Citizens United decision in her first 30 days as president, her campaign said.

Clinton was slated to announce the plan Saturday in a video message to progressive activists at the Netroots Nation annual conference, as she works to shore up support among voters loyal to Vermont Sen. Bernie Sanders who made reducing the influence of the wealthy an animating principle of his presidential campaign.

Clinton first made the pledge to overturn the decision in 2015 during the opening week of her presidential campaign. The 2010 high court ruling, which allowed unlimited corporate and union spending in elections, has helped release a flood of political money in federal, state and local contests.

In a statement, campaign officials called overturning the controversial decision a key part of Clinton’s plan to “challenge the stranglehold that wealthy interests have over our political system.”

Democratic presidential candidate Hillary Clinton (Photo: Carolyn Kaster, AP)

Clinton also pledged to take other actions long sought by campaign-finance watchdogs, including signing an executive order requiring companies with federal contracts to disclose their political spending.

Liberal watchdog groups applauded her move.

“With this pledge, Hillary Clinton is making it clear that she understands the path to the White House depends on having both the right positions on money-in-politics reforms and a clear path of action,” said David Donnelly, president of Every Voice, which supports overhauling the campaign-finance system.