Republicans and Democrats alike are running into unexpected resistance within their own parties to moving ahead aggressively on gerrymandering red and blue states ahead of the 2026 midterms.

Among Republican-controlled states, Texas, Missouri and North Carolina have acted swiftly to redraw congressional maps in their states, with the potential to swing as many as seven seats in favor of the GOP. Democrats have countered with moves to redraw the maps in California and Virginia, where an equal number of districts could be turned blue.

But the push to lock in as many seats as possible before voters elect a new Congress next year has been met with resistance or indifference in other states, including New Hampshire, Indiana, Illinois and Maryland. Even in California, some Republicans are complaining of a feeble response by party leaders to Governor Gavin Newsom’s electoral initiative.

In New Hampshire this week a state senator, Dan Innis, withdrew his bill that would have provided for a redrawing of the state’s two congressional districts in the face of resistance from Governor Kelly Ayotte, a Republican. The effort, forcefully encouraged by President Trump, could have flipped one of the two districts, both now held by Democrats.

“The timing is off for this because we are literally in the middle of the census period, and when I talk to people in New Hampshire, it’s not at the top of their priority list,” Ms. Ayotte said in an interview with a Manchester television station earlier this year.

“They want us to continue to work in the legislature on housing issues, childcare, keeping the state the safest in the nation, and making sure we have the best quality education for our children. So, I don’t believe the timing is correct for this,” she said.

In Indiana, where Republicans hold seven of the state’s nine seats, a grassroots effort is partly responsible for derailing a White House-promoted effort to turn the only two Democratic-held seats red.

While Governor Mike Braun is still hoping to go ahead, a statement from the Senate majority’s communications office to FOX59/CBS4 on Wednesday said, “the votes aren’t there for redistricting.”

Liz Brown, the assistant majority floor leader and chair of the Judiciary Committee in the Republican-led state Senate who has resisted the bid, was quoted saying, “I urge my colleagues to stand with me as we move ahead to protect our conservative values.”

A recent poll by Independent Indiana found voters opposed to redistricting by 53 percent to 34 percent, and an advocacy group, Indiana Conservation Voters, praised the Republican-led Senate for “standing strong against political pressure from Washington” and “putting Hoosiers first.”

On the other side of the ledger, state Democrats in Illinois are pushing back against the House minority leader, Hakeem Jeffries, who has been urging the lawmakers to add redistricting to the agenda before they adjourn their fall session next week.

“I think there is next to zero appetite to do it,” one Democratic state House lawmaker told Capitol News Illinois on Wednesday, while another lawmaker said, “There is no world where I see this happening.”

Apart from logistical issues concerning a fast-approaching filing deadline for next year’s primaries, the outlet cites opposition from black lawmakers who fear that new maps would spread black votes across more districts, diluting their influence. Even if the bid were to go ahead, it was expected to pick up no more than one of the state’s three Republican seats.

Further east in Maryland, Governor Wes Moore is finding it difficult to round up enough support in his heavily Democratic legislature to move forward with a redistricting scheme that could flip the state’s last remaining Republican seat.

“The General Assembly has got to be the one … to introduce and pass legislation, but they also know that they have a ready and an eager and a willing partner in the governor to make sure that we have fair maps come November,” Mr. Moore told reporters last month, as quoted by Politico.

Much of the reluctance stems from concerns that the proposed map is too much like one struck down four years ago by a judge who called it an “extreme partisan gerrymander” that violated the state’s constitution. Any new map would likely meet the same fate, given that five of the state’s seven Supreme Court justices were nominated by a former Republican governor, Larry Hogan.

Meanwhile in California, where polling shows that Mr. Newsom’s ballot initiative to allow redistricting is likely to prevail, some Republicans are complaining about what they see as an underwhelming effort by the former House speaker, Kevin McCarthy, to organize opposition to the initiative.

Mr. McCarthy pledged last summer to raise $100 million to help protect GOP lawmakers in his home state but has fallen far short of that goal, according to unidentified sources quoted by CNN.

“I think it is an opportunity that is being wasted,” one California-based House Republican lawmaker told the network.