A coalition of progressive advocacy groups descended on the U.S. capitol Wednesday with plans to engage in "mass non-violent civil disobedience" aimed at pressuring senators to allow witnesses in President Donald Trump's ongoing impeachment trial.

"We're going to put an end to Mitch McConnell's disgraceful cover-up."

—Public Citizen

The "Swarm the Capitol" event was organized by Center for Popular Democracy Action, Public Citizen, the Poor People's Campaign, Women's March, and other grassroots organizations representing hundreds of thousands of Americans nationwide.

"We are calling for a moral impeachment," Rev. William Barber, co-chair of the Poor People's Campaign, said at a press conference ahead of Wednesday's action. "That's why we're marching with our allies today."

With the #WeWantWitnesses later trending on social media, the day of action began with a silent protest inside the Hart Senate Office Building atrium at noon, according to Public Citizen. Demonstrators then marched to the steps of the U.S. Capitol building, where arrests are expected.

"Swarm the Capitol and demand John Bolton be allowed to testify," Public Citizen tweeted Wednesday, referring to Trump's former national security adviser. "We're going to put an end to [Senate Majority Leader] Mitch McConnell's disgraceful cover-up."

HAPPENING NOW: Hundreds of protesters swarm Capitol Hill to protest the GOP's impeachment cover-up.#SwarmTheCapitol #WeWantWitnesses pic.twitter.com/IX6RUUeRrB — Public Citizen (@Public_Citizen) January 29, 2020

"The American people deserve to hear all available witnesses and evidence be presented. We won't stand for this GOP cover-up!" said Jennifer Epps Addison, co-executive director and network president of the Center for Popular Democracy Action. "Senators must act decisively to protect our country, and lean into the political power harnessed by Black and Brown communities. Together we can demonstrate how powerful our popular democracy can be and how committed we are to protecting it."

Hundreds rally at the Supreme Court and the Capitol to demand a fair trial with witnesses & documents. Join your voice with theirs: Call your senators! Text CONVICT to 69866 to be connected. #NoCoverUp #WeWantWitnesses pic.twitter.com/jV6zOQL9Tt — Sierra Club (@SierraClub) January 29, 2020

As Common Dreams reported earlier Wednesday, McConnell told fellow Republican senators behind closed doors late Tuesday that he does not yet have the votes to block witnesses from testifying in Trump's impeachment trial. A vote on whether to allow witnesses is expected to take place Friday.

"The omission of witnesses and evidence in Trump's removal trial must be met with public outcry by every individual who believes in government for the people and by the people." —Rachel O'Leary Carmona, Women's MarchA Politico/Morning Consult poll released Wednesday found that 57% of the U.S. public—including 86% of Democrats and 57% of Independents—believe Trump should not be permitted to invoke executive privilege to block witnesses from testifying in the Senate trial. Just 25% of Republicans said the president should not be allowed to invoke executive privilege.

Rachel O'Leary Carmona, chief operating officer for Women's March, said, "The omission of witnesses and evidence in Trump's removal trial must be met with public outcry by every individual who believes in government for the people and by the people."

On Tuesday, a Quinnipiac University poll found that 75% of registered voters believe witnesses should be allowed to testify at the impeachment trial, and 53% of voters believe Trump is lying about his actions toward Ukraine.

"The American people need to see all the documentary evidence and hear from all potential witnesses," the progressive coalition wrote on Facebook ahead of Wednesday's demonstrations. "We will not stand for the GOP's obstruction of justice."