This story has been updated.

A comprehensive voting rights, elections and ethics bill is working its way through the Senate — and although it faces steep odds amid opposition from Republicans, it’s the furthest such legislation has gotten in Congress in a long time.

House Democrats passed their version of the bill in March. If signed into law, it would mark a huge expansion of voting rights, and a major overhaul of campaign finance and redistricting laws. Republicans say they want to stop it in the Senate.

Republicans at the state level nationwide have proposed a wide range of measures, many in response to allowances that were made for voting during the coronavirus pandemic in 2020.

The measures include curtailing eligibility to vote by mail, prohibiting the use of ballot drop boxes, and in the case of Georgia — where the GOP lost two Senate seats and which voted for a Democratic president for the first time since Bill Clinton’s 1992 win — a short-lived proposal to block early voting on Sundays. A similar measure to limit early voting on Sundays is part of a bill that was being considered by the Texas legislature until Texas Democrats walked out of the chamber to prevent a vote from being held; the provision said Sunday voting couldn’t start until after 1 p.m., seemingly targeting black voters. Texas Republicans later said the 1 p.m. start time was a typo, and should have been 11 a.m.

Those particular measures have been called a flagrant and obvious attempt to disenfranchise Black voters in the state, and it didn’t make the final version of the bill Georgia Gov. Brian Kemp (R) signed into law. State Rep. Barry Fleming (R), the chairman of Georgia’s House Special Committee on Election Integrity, said his committee’s mission was to “restore the confidence of our public in our elections system,” an allusion to the false claims spread by former president Donald Trump about voter fraud in the 2020 election.

GOP officials in Arizona, Florida, Michigan, Pennsylvania, Texas and Wisconsin — all states that could have an impact on future presidential elections — are also considering legislation that would restrict voting.

That’s why Democrats are moving forward with their bill at the national level, and although it may not pass in the Senate, they want to put pressure on Republicans, who have called it a political power grab.

“It is not designed to protect Americans’ vote — it is designed to put a thumb on the scale in every election in America, so that Democrats can turn a temporary majority into permanent control,” House Minority Leader Kevin McCarthy (R-Calif.) said when the bill passed the House in March.

Ahead of the vote on H.R. 1, Democratic lawmakers rallied on the Capitol steps on March 3. The bill is expected to face opposition in the Senate. (Joy Yi/The Washington Post)

Here’s what the bill actually contains:

A set of national voter registration and mail-in voting standards: H.R. 1 requires the chief election official in each state — the secretary of state in most — to establish an automatic voter-registration system that gathers individuals’ information from government databases and registers them unless they intentionally opt out.

And it says it’s the government’s responsibility to keep that information up to date, based on information from agencies such as state motor vehicle administrations, agencies that receive money from Social Security or the Affordable Care Act, the justice system and federal agencies, including the Department of Veterans Affairs, the Defense Department, the Social Security Administration and others.

The law also would guarantee voters same-day registration either at early-voting sites or at precincts on Election Day. Each state would be required to allow at least 15 days of early voting for federal elections, for at least 10 hours a day with at least some time before 9 a.m. and after 5 p.m. The law would limit how states can purge voter rolls.

Nonpartisan redistricting commissions: In an attempt to get rid of gerrymandering, the law would require each state to use independent commissions (not made up of lawmakers) to approve newly drawn congressional districts. The commissions would each include five Democrats, five Republicans and five independents, requiring bipartisan approval for districts to be allowed.

“Regardless of whether it’s a red state or a blue state, we are seeing significant manipulation in the legislative redrawing of districts,” said Tom Lopach, chief executive of the nonpartisan Voter Participation Center, which has advocated for the bill. “H.R. 1 presents an opportunity for everyone to get onboard with independent, unbiased and balanced redistricting that frankly is good government.”

It would also give the public a new level of scrutiny, and a chance to object to poorly drawn districts. The law would require a public comment period and give citizens a legal basis to challenge gerrymandering. (Currently, gerrymandering challenges have to be made on constitutional grounds, and if a law were passed, there would be a clearer argument to present in court against gerrymandered districts.)

Big changes in campaign finance law: H.R. 1 would require super PACs and “dark money” groups to disclose their donors publicly, a step Democrats say would eliminate one of the most opaque parts of the U.S. election process. It would establish a public funding match for small-dollar donations, financed by a fee on corporations and banks paying civil or criminal penalties.

It would also require Facebook and Twitter to publicly report the source and amount of money spent on political ads.

New ethics rules for public servants: The bill would create the first ethics code for Supreme Court justices, to be created within a year of the bill’s passage.

It would also stop a much-debated practice in Congress: When a member of Congress settles a sexual harassment or discrimination lawsuit, in certain cases they can use taxpayer money to settle. H.R. 1 would prevent taxpayer money from being used for such settlements.

The bill also would create more oversight on lobbyists and foreign agents.

A requirement that presidential candidates disclose their tax returns: This one is a little more relevant to recent events. Democrats have been frustrated for years that Trump never released his tax returns, and H.R. 1 would require it by law.

Can it pass in the Senate?

Senate Democrats plan to move the bill forward, but Republicans in the chamber have been very public with their pledge to fight it forcefully. A similar House bill was passed in 2019, and then-Majority Leader Mitch McConnell (R-Ky.) refused to bring it to the Senate floor for a vote.

Senate Majority Leader Charles E. Schumer (D-N.Y.) has promised to end what he called McConnell’s “legislative graveyard,” and bring more bills passed by the House to the floor to force votes. But if they want it to pass, Democrats don’t have a lot of options. Bringing the bill to the Senate Rules Committee is a step that forces committee Republicans on the record as being for, or more likely against it, and a full Senate vote could do the same — but that isn’t the kind of political pressure that seems likely to get Democrats to the 60 votes they’d need to send the bill to President Biden’s desk.

Unlike the coronavirus relief package Democrats passed in March, for which Schumer needed only 50 votes plus Vice President Harris’s tiebreaker, H.R. 1 isn’t being passed through the special reconciliation process that requires a simple majority.

Democrats’ other option is to eliminate part or all of the legislative filibuster — a political bombshell that would allow them to pass much more legislation with just 50 votes and Harris’s tiebreaker.

Even if they do pass it, it would probably come up against lawsuits. The conservative Heritage Foundation has called many of the bill’s provisions unconstitutional, and given how opposed congressional Republicans are to it, legal challenges seem inevitable.