New York Will Soon Lose 1 House Seat. The G.O.P. Might Lose 5.

Seven years ago, New Yorkers voted decisively to empower a new bipartisan commission to do what self-interested politicians could not: draw new congressional district lines that were not gerrymandered to favor a particular party.

But as the panel prepares to unveil its proposed maps for the first time on Wednesday, Democratic lawmakers in New York and Washington are already laying the groundwork to cast them aside — plotting to use their supermajorities in Albany to draw new district boundaries for the next decade that might eliminate as many as five Republican-held seats.

The end result could drive one of the most consequential shifts in power in the country this redistricting cycle, the first since New York voters approved a 2014 ballot measure to curb gerrymandering.

Under the most aggressive scenarios, Democrats could emerge from 2022’s midterm elections with control of as many as 23 of New York’s 26 House seats in an all-out effort to prop up their chances of retaining control of Congress. For the first redistricting cycle in decades, Democrats control the Legislature and governor’s office, giving them the freedom to reshape districts without having to compromise with Republicans, who long held a lock on the State Senate.

“New York might be the biggest redistricting weapon for either party in the country,” said Dave Wasserman, a national elections analyst with the Cook Political Report.

Wielding it will almost certainly raise howls of protest from Republicans and expose Democrats to legal challenges and political charges that they are hypocritically turning their backs on the party’s promise to end gerrymandering, the practice that allows politicians to draw legislative lines in their party’s favor.

Just Monday, Chuck Schumer, the state’s senior senator and the Democratic majority leader in Washington, sought to rally senators on Capitol Hill in favor of a sweeping national elections bill that would override state laws like New York’s and outlaw “vicious gerrymandering, which further threatens to divide our politics.”

Yet with Republicans preparing to use their control of states like Texas, Florida and Georgia to pile up a dozen or more new red seats, Democrats seem intent on using New York’s laws to their advantage. Mr. Wasserman said that New York’s gains would likely be greater than others whose process was under single-party control, such as Texas, because those states have already been more thoroughly gerrymandered.

Top officials in Albany have privately indicated to Democrats in the congressional delegation that they intend to consult with them on how to draw the new maps, according to two Democrats directly familiar with the matter who requested anonymity to detail the private conversations. Though the Constitution gives the commission the first shot at drawing maps, lawmakers in Albany have broad leeway to disregard the panel’s work and create their own.

They are expected to extend particular deference to Representatives Hakeem Jeffries, the top-ranking New Yorker in the House, and Sean Patrick Maloney, who is leading Democratic efforts nationally to maintain control of the House.

The targets include Republican districts stretching from the eastern tip of Long Island, through Staten Island and up to the far rural reaches of northern and western New York, where the 2020 census recorded population loss that will cause New York to lose one congressional district next year.

Democratic members of the state’s delegation to Washington held a virtual meeting on Friday to begin discussing the process, a complex balancing act of parochial concerns, legal mandates and political interests. Most declined to comment for this article, as did their Republican counterparts.

Mike Murphy, a spokesman for the Senate Democratic majority, denied that Washington would play a role. “Anyone suggesting otherwise is misinformed,” he said. “At best.”

Even so, Democrats in Albany are keenly aware of the intricacies of the task before them. Gov. Kathy Hochul, a former House member who lost her seat after the last redistricting cycle, has indicated she has no qualms about using the party’s sway in New York to extend Democratic power in Washington.

“It’s impossible not to be cognizant of the national implications of what we do,” said State Senator Michael Gianaris, a Queens Democrat who co-leads the New York State Legislative Task Force on Reapportionment and Redistricting, the body that would draw maps if the independent commission fails to reach an agreement that the Legislature can accept.

“There’s still a lot we don’t know,” he added. “Is the commission going to even agree on a map or break down on partisan lines? How good a job do they do?”

The murkiness around redistricting is hardly new. Voters created the independent commission after the last redistricting cycle went so badly off the rails that the courts had to step in to draw the congressional maps themselves. To break through a related impasse with Republicans then controlling the Senate, Gov. Andrew M. Cuomo hatched a deal to create the bipartisan panel by constitutional amendment.

Well before the commission began its work though, criticism began to mount. Good governance advocates denounced the panel, which requires a supermajority of members to pass anything, as ineffectual and designed to fail. A state judge ruled in 2014 that proponents ought not even refer to the panel as “independent,” since the Legislature and governor must approve its work.

Now, Democrats essentially have carte blanche to draw the lines as they see fit, as long as they can hold their members together.

“There’s the official process and then there’s the real process. That’s always been the case,” said Blair Horner, the executive director of the New York Public Interest Research Group. “We’re in the Kabuki part of redistricting.”

Democratic Party leaders will have to decide in the months ahead how aggressively to pursue Republican seats.

On Long Island, for example, Democrats could shuffle lines to create three blue seats where there are currently two and limit Republicans to a single suburban district anchored on the South Shore.

Democrats are likely to take aim at the lone Republican-leaning seat in New York City, the 11th District, anchored on Staten Island and parts of Brooklyn. Representative Nicole Malliotakis, a first-term congresswoman, holds the seat now, but adding more liberal sections of Brooklyn or even Lower Manhattan could make it untenable for a Republican.

The most significant gains could come upstate, the most likely region to lose a district altogether. Mr. Wasserman suggested mapmakers could try to pool voters into two conservative mega-districts. At the same time, the party could shore up two of its incumbents in Hudson Valley swing seats, Mr. Maloney and Representative Antonio Delgado.

One red seat could be created in western New York by combining the vast Southern Tier district held by the retiring Republican Tom Reed with territory between Buffalo and Rochester, represented by Chris Jacobs, also a Republican. A second could be rooted in the Adirondacks, combining areas of central and northern New York represented by Republicans Claudia Tenney and Elise Stefanik, a rising star who is now her party’s top-ranking woman in Washington.

Targeting the region’s other remaining Republican, John Katko, would be less straightforward. One of the few remaining moderate Republicans in the House who voted to impeach former President Donald J. Trump, Mr. Katko has repeatedly won his Syracuse-based district despite Democratic advantages there.

The commission will also propose new lines for the State Assembly and Senate, but lawmakers in Albany could just as easily toss them out to produce a result more favorable to Democrats looking to lock in their dominance for years to come. Democratic senators, in particular, are eyeing changes to districts that they say Republicans gerrymandered last cycle when they still controlled the chamber.

State Senator Robert G. Ortt, the Republican leader, said he was troubled by signs that Democrats would undermine the process chosen by voters before it began. He suggested that Democrats, led in Washington by Speaker Nancy Pelosi, had few other options to cling to power:“They know that the only way that she remains speaker is if they do this type of gerrymandering,” he said.

But the cold political calculus of redistricting means that even safe Democratic districts may see changes.

Preparing for her third successive primary challenge from the left, Representative Carolyn Maloney, the Democratic chairwoman of the powerful House Oversight and Reform Committee, is angling to shed thousands of progressive voters from her district. Her proposal: offloading sections of Williamsburg, Brooklyn, home to young and Latino voters, and potentially parts of Astoria, Queens, while keeping her political base intact on Manhattan’s wealthy East Side.

Ms. Maloney, 75, has reason for optimism — at least when it comes time to settle on the lines. In addition to being a committee leader in Washington and one of the longest-serving New Yorkers in Congress, she was once landlord in Washington to Ms. Hochul, who must sign off on the final maps.

For now, representatives of the House Democratic campaign arm in Washington have discouraged members from hiring lobbying firms, as they have in past cycles, or making direct entreaties to the commission or their counterparts in the Assembly. The commission’s work, they have said, should run its course first.

“It’s the Republicans who want to stack the deck, but you give me fair lines, and we’re going to do just fine,” said Mr. Maloney, the Democratic campaign chief. “I have every confidence that we’ve got good, good partners in Albany.”

Katie Glueck contributed reporting.