The warning blared over the loudspeakers of a Chicago-area hotel around 7:30 a.m. on Wednesday: bomb threat, evacuate immediately.

Dozens of Democratic lawmakers from Texas, along with hundreds of other guests, rushed outside as state and local police officers scoured the hotel and conference center in St. Charles, Ill., before determining the threat had been false.

The episode, though not traced back to any political opponents, was emblematic of the pressure mounting on the lawmakers since they left their state on Sunday to prevent Republicans from passing an aggressively redrawn congressional map at the behest of President Trump.

Illinois, a Democratic state, was supposed to be a haven, but Texas Democrats have been unable to escape escalating legal and political threats that have gone further and come faster than many of them had anticipated, based on earlier walkouts in 2021 and 2003. Now they are wondering just how long they can hold out — and hoping to make it to the end of the special legislative session they left behind, which is set to end Aug. 19.

“They’re using hardball, unconventional, authoritarian tactics that we didn’t see in 2021,” said State Representative Ron Reynolds, a Houston Democrat who was part of the group at the hotel in St. Charles. “People are concerned. We’re looking over our shoulder.”

Those tactics keep coming.

On Tuesday, Senator John Cornyn, Republican of Texas, called for F.B.I. agents to round up the Democrats who were camped out in Illinois. Mr. Trump seemed to endorse the idea of federal agents getting involved — “They may have to,” he said that evening — though the agency has not commented.

The same day, the state’s attorney general, Ken Paxton, took steps to remove the absent lawmakers from office. That initially drew scoffs. Then hours later, Gov. Greg Abbott filed an emergency petition with the Texas Supreme Court asking for the state’s high court to vacate the Texas House seat of the walkout’s leader, State Representative Gene Wu of Houston, claiming he had abandoned it.

The state’s high court gave Mr. Wu until Friday evening to respond. Friday is also the deadline set by Mr. Paxton for the absent Democrats to return, before he begins removal proceedings against many of them.

“We are in uncharted territory,” Mr. Paxton said in an interview on Newsmax.

On Wednesday, Mr. Paxton kept up the pressure, announcing that he had begun an investigation into Powered by People, a political organization run by former U.S. Representative Beto O’Rourke, a Democrat, over potentially funding the walkout, which he darkly suggested was an illegal bribe.

Mr. O’Rourke, in a statement, was defiant. “The guy impeached for bribery is going after the folks trying to stop the theft of five Congressional seats,” he said, referring to the 2023 impeachment proceeding against Mr. Paxton, which ended in his acquittal in the State Senate.

This was not how the Democratic lawmakers expected things to happen. Most anticipated the latest walkout to follow patterns of the past: first frustration from Republicans, then some civil arrest warrants that are unenforceable outside Texas, and, finally, after several weeks, a reluctant capitulation as the Democrats returned to watch Republicans pass their bills.

Republicans have not stuck to that script. And several Texas Democrats said privately that they anticipated the walkout would last only through the end of the special session. Eventually, they conceded, the Republican effort to push through a rare and overtly partisan mid-decade redistricting would succeed, possibly by month’s end.

Democrats have played their part, with daily news conferences in Illinois, New York and Massachusetts, and acts of defiance and solidarity.

On Wednesday, after unveiling a butter cow sculpture at the Illinois State Fair, Gov. JB Pritzker, a Democrat, delivered another broadside at Republicans, saying, “They know they’re going to lose in 2026 if they don’t breach the rules, if they don’t cheat.”

But Texas Democrats have also been forced to defend themselves against actions of the Republican leaders in their state.

“Denying the governor a quorum was not an abandonment of my office,” Mr. Wu said in a statement after Mr. Abbott’s move to remove him from office. “It was a fulfillment of my oath.”

One of the dynamics that has separated this walkout from the past has been on the Republican side. Mr. Cornyn and Mr. Paxton are locked in a bruising primary battle for the U.S. Senate next year, and each has appeared eager to show how tough he can be on the absent Democrats.

The investigation of Mr. O’Rourke’s group is part of another line of attack from Texas Republican leaders, who have suggested that the absent Democrats, and those supporting them financially, may have violated criminal bribery laws. Mr. Abbott has directed the Texas Rangers to investigate.

Some Republicans in the Texas House have been discussing the possibility of starting their own investigation. “I think it’s the right move,” said State Representative Mitch Little, a Dallas-area Republican.

Despite the pressure, Democrats have achieved one thing already. By drawing national attention to the Republican gerrymandering effort, they have raised the stakes and spread the conflict far beyond Texas.

“How much time to do we need to give other states to organize their redistricting efforts? Every day gives another state the courage to determine that,” said State Representative Trey Martinez Fischer, a San Antonio Democrat. “If there’s going to be a Donald Trump race to the bottom, then we’re going to see them at the finish line.”

To that end, Democratic leaders in California said they were looking at putting together their own maps, redrawn to favor Democrats, in time to get them on the ballot in November. On the flip side, Republican states like Missouri and Indiana are considering calling special sessions to redraw their congressional maps.

In Massachusetts on Wednesday, Democratic lawmakers from across the country gathered at the State House to hammer a single message: Texas is first. Your state is next.

“We’re proud of our independent system for picking districts, but we can’t roll over while the Republicans cheat,” said Cecilia Aguiar-Curry, the State Assembly majority leader from California, which has rules mandating that congressional districts be independently drawn.

Gov. Gavin Newsom has said he would like to suspend those rules and have voters approve a new map that would go into effect only if Texas passed its redrawn map.

Mr. Newsom may know whether Texas gives him the go-ahead fairly soon. The Texas House needs at least 100 of its 150 members to be present to hold votes. If only a handful of the 54 Democrats who were absent this week were to return to Austin, the walkout would effectively be over.

“We are undeterred,” said State Representative Chris Turner, a Dallas-area Democrat. “The commitment in our group is to let this special session expire. That’s been the focus.”

After that, he said, he anticipated the fight would eventually move to the courts.

“The battlefield is in the Texas Legislature right now,” he said. “Ultimately, if the map passes in Texas, the next battle will be in the federal courts.”

Julie Bosman contributed reporting from Chicago and Chris Hippensteel from Massachusetts.