The US Senate takes up the flashpoint issue of voting rights Tuesday, with Democrats and Republicans divided over who gets to vote and how in the wake of an election marred by Donald Trump's baseless allegations of fraud.
The procedural vote's outcome is in little doubt: Republicans are expected to block a sweeping package which would amount to the most expansive federal election reform in decades.
But Democrats are bringing the "For the People Act" to the floor as a test vote, in reaction to controversial efforts by Republicans to enact strict new voting laws in dozens of states.
The Democrats' historic bill is aimed at ensuring Americans can vote by mail, plus have full access to early voting and use of ballot drop boxes.
A version of the bill, which also reforms campaign finance laws and attempts to thwart gerrymandering, or the partisan redrawing of district lines, passed the House of Representatives on a party line vote.
But the text appears doomed in the Senate, where Republicans are united against the measure, ensuring the issue remains a political imbroglio into the 2022 midterm elections and beyond.
There was worry that Democratic moderates, led by Senator Joe Manchin who is opposed to the vast expanse of the bill, would not support it.
But Manchin announced he would vote to begin debate on the measure, likely putting all Democrats on board, after leadership agreed to introduce a "commonsense compromise" that he proposed.
"I remain committed to finding a bipartisan pathway forward because the future of our democracy is worth it," Manchin said in a statement.
Manchin's compromise maintains most of the Democratic bill's provisions, but allows a key concession -- voter identification requirements -- in a bid to win over Republicans.
Democrats control the 50-50 Senate. But even if all Democrats support the bill, it would fall short of the 60 votes needed to move it forward.
Senate Majority Leader Chuck Schumer, highlighting what he called "a wildfire of Republican voter suppression laws sweeping across the country," called out his GOP rivals for seeking "blatant" partisan electoral advantage.
Schumer said Republicans, keenly aware that Trump feels mail-in voting and other expansive voting rules led to his defeat, "are deliberately targeting all the ways that younger, poorer, non-white and typically Democratic voters access the ballot."
The Senate vote is set for 5:30 pm (2130 GMT). Even if it fails as expected, Democrats hope to claim a moral victory and highlight Republican opposition to basic democratic principles of voting rights for all.
The White House has acknowledged the vote will fail, but nevertheless issued a statement of support, as it highlighted how Americans' right to vote "is under assault" thanks to moves by Republican state legislatures.
"In state after state, new restrictive laws on voting, and efforts to replace non-partisan election administration with partisan processes designed to overturn the will of the voters have become more widespread," the White House budget office said.
Republicans though remained firmly against the Democratic effort.
Their bill is a "transparently partisan plan to tilt every election in America permanently in their favor," said top Senate Republican Mitch McConnell.
"It's a recipe for undermining confidence in our elections, remaking our entire system of government to suit the preferences of one far end of the political spectrum."
Biden has warned that American democracy is imperiled by the Republican efforts, but progressive activists are complaining that Biden is not doing enough.
"Is saving democracy a priority for this Administration or not? Right-wing zealots are systematically dismantling our democratic institutions," Ezra Levin, co-executive director of progressive election group Indivisible, said Monday on Twitter.
"It's time for the President to get off the sidelines and into the game, or we're all going to lose."
Meanwhile Trump himself continues to launch attacks on the 2020 election process, using provocative language that critics say is intended to raise doubts about America's voting system.
"The 2020 Presidential Election was rigged!" the defeated president seethed in a Tuesday statement.