The impeachment of the Texas attorney general, Ken Paxton, by a majority of his fellow Republicans has exposed an undercurrent of division and discontent that is roiling the Republican Party in the most populous state where it still enjoys near total political control.
While the vote in the House of Representatives on Saturday tore suddenly through the heart of Texas politics, the underlying resentments had been gathering force for months, if not years, not over individual personalities but over how Republicans should use their power and what shape the party should take in the future.
The fight over Mr. Paxton’s impeachment, which drew in national Republican figures including former President Donald J. Trump, offered a stark demonstration of two increasingly warring currents in Republican politics.
Though the eruption was unexpected — as of a week ago there was little public indication that an impeachment could be imminent — it was the culmination of a session of the Texas Legislature, where Republicans dominate both chambers, that was defined by steadily increasing intraparty acrimony.
“It’s the battle between the version of the Republican Party under Trump and the version of the traditional Republican Party,” said Jeronimo Cortina, a professor of political science at the University of Houston. The fight is especially urgent in Texas, he added, because increasing urbanization and demographic changes threaten the party’s dominance over Democrats.
“The question for Republicans is, do you want to stay in government for a couple of years” by catering to a shrinking pool of aging voters? Mr. Cortina said, describing the party’s most conservative members. “Or do you want to invest in having a Republican Party that’s going to have a future in Texas?”
At the impeachment proceeding, some of the most conservative members of the Legislature found themselves railing against the power politics of their own moderate leadership in the House.
“Don’t end our session this way,” Representative Tony Tinderholt said as he implored fellow Republicans to vote against impeaching Mr. Paxton, an archconservative who has made a national reputation fighting Democrats on immigration, health care, voting and other issues. “Don’t tarnish this institution.”
In the end, 60 out of the 85 Republicans in the Texas House disagreed and voted to impeach Mr. Paxton over accusations of corruption, bribery and abuse of office, temporarily removing him from office pending a coming trial in the State Senate.
By the close of the session, which officially ends on Monday, the conservative juggernaut that had swept in a wave of legislation during lawmakers’ last session two years ago encountered significant pushback, not only from Democrats but also from fellow Texas Republicans willing to draw a line in the sand on some issues.
A special session to address some of the enduring divides — on education funding, property taxes, border security and renewable energy regulation, not to mention the fate of Mr. Paxton — appeared all but certain.
Anger among conservative activists and hard-right lawmakers had been building for months as they watched many of their priorities sail through the State Senate only to become stymied in the Texas House.
The two chambers have often been in conflict in recent legislative sessions, with the House acting as a more moderate check to the hard-right leadership of Lt. Gov. Dan Patrick, who presides over the Senate.
This year, though, the resentments appeared greater than usual.
Most of the eye-catching conservative proposals came out of the Senate, which rapidly passed a series of hard-line bills, including ending tenure in state universities, creating new restrictions on teaching about sex and gender similar to a highly contentious law in Florida, adding extensive new voting restrictions in Houston and putting the Ten Commandments in every public school classroom in Texas.
But tensions escalated as the weeks passed and deadlines approached. Many of the Senate priorities languished and then officially died in the House, to the consternation of some of its most conservative members.
A dispute over how best to cut property taxes for Texans — a seemingly easy lift in a tax-averse state that was sitting on a more than $30 billion budget surplus — led Mr. Patrick to begin calling Dade Phelan, the House speaker, who had a different plan, by one of the more insulting nicknames one can think of in Texas politics: “California Dade.”
Mr. Patrick even enlisted Mr. Trump to weigh in. The former president adopted the nickname and endorsed Mr. Patrick’s property tax plan.
That tactic did not result in a breakthrough in negotiations, though it did focus a spotlight on Mr. Phelan, a Republican from the city of Beaumont. The House and Senate agreed on Saturday to a spending plan that set aside more than $17 billion for a tax cut, but they still have been unable to come to terms on how it would actually work.
The California nickname was replaced last week in certain conservative activist circles by “Drunk Dade,” after Mr. Paxton accused Mr. Phelan of being intoxicated during a recent late-night session of the House. Mr. Phelan denied the accusation, which was leveled just as it became clear the House had secretly been investigating Mr. Paxton.
Mr. Trump again condemned Mr. Phelan on Saturday before and after the impeachment vote, vowing to “fight” any Republicans who voted for impeachment.
The Republican Party of Texas, which has positioned itself to the right of many state elected officials, has been attacking Mr. Phelan since the start of the session, running radio ads against him in February because he continued a longstanding practice of allowing Democrats to chair some committees.
But the conservative discontent goes deeper.
“I think of it as part of an evolution rather than anything specifically focused on Phelan,” said Cal Jillson, a political science professor at Southern Methodist University in Dallas. “There is growing aggravation among social conservatives that they don’t have the kind of control in the Texas House as Patrick does in the Senate to move a social conservative agenda.”
The divisions spilled into the open on Saturday in a display rarely seen in the current atmosphere of hyper-partisanship: a formal proceeding, governed by Republicans, holding to account a popular but scandal-plagued politician from their own ranks. Its speed was remarkable: Just days after the investigation into Mr. Paxton was first publicly discussed, he had been impeached.
“I’ve been watching this stuff for a long time,” Mr. Jillson said, “and I have never really seen such a major development erupt so unexpectedly.”
While lawmakers debated in Austin, Gov. Greg Abbott — who has not commented on the impeachment — toured the state trying to drum up Republican support for his top policy goal: a program to use public money to pay for private schools.
In pushing for what is variously known as school vouchers or school choice, Mr. Abbott visited Christian schools and churches around Texas and appeared with the influential Texas Public Policy Foundation, a conservative nonprofit backed by important Republican donors.
The governor, who has tried to thread the needle between the party’s factions, had support from the State Senate, which passed a bill to enact school choice using so-called education savings accounts, or E.S.A.s. But the effort encountered resistance from many rural Republicans, particularly in the Texas House.
In a fit of pique this month, the governor threatened to use his power to force lawmakers to come back for another legislative session after this one ends.
Hours after the impeachment vote on Saturday, it became clear that he would have to if he wanted to save his school funding plan: In an 11th-hour attempt, Senate Republicans failed to force through a school voucher plan that tacked it onto a House bill increasing school funding and teacher pay.
“Teacher raises are being held hostage to support an E.S.A. plan!” Representative Ken King, a rural Republican from the Texas Panhandle and the bill’s sponsor, said in a statement on Saturday. “What the governor and senate has done is inexcusable.”
Despite the rifts, some of the pieces of contentious legislation made it through both chambers. A bill to ban hormone therapies, surgeries and other medical treatments for transgender children passed. So too did a measure — derided by Democrats as the “Death Star bill” — that would prevent local governments, including major cities run by Democrats, from making their own local ordinances on certain issues, such as worker protections. And legislators agreed on a bill to allow school districts to hire religious chaplains as counselors.
Even if Mr. Abbott does not call them back, lawmakers will be returning to the Capitol for a unique sort of special session and one that was likely to further test the bonds of Republicans: the trial in the Senate of Mr. Paxton.
The date has yet to be set for what will be the first impeachment trial of a statewide official in Texas in more than a century, one in which the dividing lines in the Republican Party are likely to be front and center. Representatives of the House present the case. Mr. Paxton will have a chance to defend himself. And the senators — including Mr. Paxton’s wife, Angela, and his longtime friend, Bryan Hughes, unless they recuse themselves — will act as a jury.
Mr. Patrick, who will preside over the trial and set its rules, is a firebrand conservative and former talk radio host whose supporters and donors come from the same wing of the party as Mr. Paxton. But on the subject of the trial, Mr. Patrick has maintained a neutral posture so far. “The senators, all 31 senators, will have a vote,” he said in an interview on the Y’all-itics podcast. “We will all be responsible as any juror would be.”