WASHINGTON (AP) — Dozens of left-leaning organizations are asking Senate Majority Leader Chuck Schumer to schedule a new vote this month on Democrats' sweeping voting and elections bill, a top priority for the party that Republicans blocked from debate last month.

In a letter sent to the New York Democrat on Monday, the groups urged him to once again bring the bill to the Senate floor. But this time, they are asking Senate Democrats to weaken filibuster rules, which require 60 votes to advance most legislation, and push the measure through on a party-line basis, with Vice President Kamala Harris casting the tiebreaking 51st vote.

"The only thing standing in the way is the outdated and abused filibuster," states the letter, which was signed by roughly 90 different groups, including the good-government group Common Cause, Our Revolution, the League of Conservation Voters, the Communications Workers of America union and MoveOn.

The letter is one piece of a broader summer campaign to pressure congressional Democrats to change the filibuster and pass their voting bill, which they've touted as a powerful counterweight to an effort in Republican-controlled states to adopt new voting restrictions.

Congressional offices have been flooded with calls, and numerous rallies have been held.

On Monday, a group of Democratic state lawmakers from Texas, where a special session of the legislature is underway to enact voting restrictions, fled the state for Washington, D.C. Their aim was twofold: to deny Texas Republicans a quorum needed to conduct business and to shine a light on the state-level efforts.

Last week, a group of civil rights activists met with President Joe Biden about the issue and publicly called on the White House afterward to get more involved.

"There is absolutely growing pressure across the country to eliminate the filibuster as a weapon (Senate Minority Leader Mitch) McConnell can use to block progress," said Eli Zupnick, a spokesperson for the group Fix Our Senate, which advocates for filibuster changes and helped organize the letter.

They face a tough road ahead. There isn't enough support in the Senate Democratic caucus to eliminate the filibuster, with moderate Sens. Joe Manchin of West Virginia and Kyrsten Sinema of Arizona among those opposed, but most are open to changing the Senate's rules. Without changing the filibuster, it is unlikely that Democrats will be able to advance the bill in the face of unified Republican opposition.

Biden's White House has characterized the issue as "the fight of his presidency." But Biden, too, opposes eliminating the filibuster.

"The President's view continues to be aligned with what he has said in the past, which is that he has not supported the elimination of the filibuster because it has been used as often the other way around," White House press secretary Jen Psaki said Monday.

Meanwhile, the window to pass and implement the bill before the 2022 midterm elections is closing.

Democrats took unified control of Washington in January and made passing the voting bill a top priority. Their measure, known as the For the People Act, would touch on virtually every aspect of how elections are conducted, striking down hurdles to voting that advocates view as the civil rights fight of the era, while also curbing the influence of money in politics and limiting partisan influence over the drawing of congressional districts.

Schumer has said multiple times that failure to pass the measure "is not an option."

But the bill languished in the Senate for months after swiftly passing the House. Republicans, who universally oppose it, argue it is overreach that would bring about a massive federal intrusion into the way states conduct elections.

The group behind the letter echoed Schumer's calls for action.

"We agree with your repeated promise that 'failure is not an option' when it comes to voting rights," the letter states. "To ensure progress in the face of partisan obstruction, we, the undersigned organizations, urge you to hold another vote on voting rights legislation like the For The People Act before the August recess."