The aggressive push by President Trump and Republicans in Texas to squeeze as many as five House Democrats out of office before a single vote is cast in the 2026 midterm elections has opened up a new chapter in an era of unconstrained partisan warfare.

For six months, Democrats have watched, sometimes haplessly and sometimes hopelessly, as Mr. Trump and his allies have bent much of the country’s political, legal and educational systems to his will.

But the bald attempt to redraw the Texas congressional map to shore up House Republicans has pushed many Democrats, including some longtime institutionalists, to a breaking point. Now, they are vowing to “fight fire with fire” and even to embrace some of the very gerrymandering tactics they have long decried as anti-democratic.

“The Texas Republicans are taking us on a race to the bottom,” said Representative Jamie Raskin, a Maryland Democrat who lamented in an interview that his party must reluctantly participate in “this rotten system.”

Voters are the immediate casualty in this escalating arms race, reduced almost to bystanders as Republicans essentially admit to trying to determine the outcome of Texas races long before the elections are held.

The result is a democracy determined less by public opinion than by raw political might.

Mr. Trump has pressed Gov. Greg Abbott of Texas and Republican state legislators to redraw their lines, with a draft map released on Wednesday that all but erased three urban Democratic seats and forced two other incumbents in South Texas into more Republican terrain. The special legislative session Mr. Abbott called lasts until late August, but votes could come in the coming week.