In a Texas G.O.P. at War With Itself, the Hard Right Is Gaining

Republican hard-liners in Texas thought this year’s primary elections would be the moment when, after years of trying, they would finally be able to take decisive control of the State Legislature.

They fell just short.

Though more than a dozen Republican incumbents fell to more conservative challengers, the party’s old guard rallied to protect the Texas House speaker, Dade Phelan, from being toppled by an activist endorsed by former President Donald J. Trump.

That victory in a runoff on Tuesday, by a margin of fewer than 400 votes out of more than 25,000 cast, staved off, at least for now, what might have been a swift transformation of the Texas House, which has long been a moderating force in state politics.

How long the House would remain that way was one of the biggest questions emerging from Tuesday’s election. Though Mr. Phelan and a few other high-profile targets avoided defeat this time, the party’s hard right remains confident that its power has yet to peak.

Across Texas, challengers have ousted a total of 15 Republican incumbents from the State House of Representatives in this cycle: Nine fell in primaries in March, and six more in runoffs on Tuesday.

“The party is moving in my direction,” said Representative Steve Toth, a Republican from the Houston suburbs who is aligned with Attorney General Ken Paxton, a leader of the party’s more conservative wing. Mr. Toth spoke on Tuesday outside a polling location in Vidor, Texas, wearing a red “Keep America Great” hat.