Sen. Bernie Sanders and other leaders in Congress on Wednesday came together to boost a growing nationwide grassroots movement to undo a Supreme Court ruling that opened the floodgates for corporate campaign spending. Sanders is the chief Senate sponsor of the Saving American Democracy Amendment to overturn the 2010 ruling in Citizens United v. Federal Election Commission. He was joined by Sens. Chuck Schumer and Tom Udall (D-N.M.) at a Summit on Overturning Citizens United. House members participating in the summit included Rep. Ted Deutch (D-Fla.), the House sponsor of a constitutional amendment identical to Sanders’.

The rise of so-called Super PACs in this year’s Republican presidential primary contests “illustrated the catastrophic effects” of unlimited independent expenditures, Sanders said. “We’ve seen campaigns propped up by a single donor,” he added. “We have seen groups accept millions of dollars from undisclosed donors, and billionaires openly saying they plan to pour money into the upcoming general elections. This is not what democracy is supposed to be about.”

Sanders warned of the “grave danger” to American democracy posed by the Supreme Court ruling treating corporations as if their “speech” deserves First Amendment free-speech protection equal to actual persons. “There comes a time when an issue is so important that the only way to address it is by constitutional amendment.”

Other proposals have been advanced to amend the Constitution and to enact new legislation to limit the court ruling’s impact by requiring greater disclosure of campaign expenditures. “While there are some differences in approach and language,” Sanders said, “we all agree on the most important thing - that Citizens United is an affront to our democracy and must be overturned.”

Momentum is growing. Hawaii and New Mexico have passed resolutions calling on Congress to overturn Citizens United. Resolutions are pending in 17 other states. Last week, for example, the Vermont Senate passed a measure that echoed resolutions adopted by 64 Vermont communities at town meetings in March. More than 147 cities across the country, from Portland, Maine, to New York City to Boulder, Colorado, to Portland, Oregon, have passed resolutions. Attorneys general from eleven states recently joined the movement, sending a letter to congressional leaders calling for a constitutional amendment to reverse Citizens United.

Sanders called for continued grassroots efforts across the country. “It is important that regular voters get engaged and convince their towns, cities, and states that this issue matters. We need to reverse the disastrous Citizens United decision as soon as possible and it is going to take a constitutional amendment to do it.”