AUSTIN, Texas — Democrats hoping for some encouraging signs in Texas did not find any on Saturday in a special election to fill a vacant congressional seat. Instead, they found themselves locked out of a runoff that will now see two Republicans battle for the seat in northern Texas.
The two Republicans — Susan Wright, who was endorsed by President Donald J. Trump, and State Representative Jake Ellzey — emerged as the top vote-getters in a 23-candidate, all-party special election to replace Mrs. Wright’s husband, U.S. Representative Ron Wright, who this year became the first congressman to die of Covid-19.
Jana Lynne Sanchez, a Democrat who made a surprisingly strong showing for the seat in 2018 and was considered by many as a likely cinch for the runoff, came in a close third, leaving the two Republicans to fight for the seat that their party has controlled for nearly four decades.
Democrats who needed a strong turnout to be competitive did not get one. They were hoping for signs of weakness in the Republican brand because of the state’s disastrous response to the brutal winter storm in February or any signs of weariness with Mr. Trump, but they did not see that, either.
Michael Wood, a small-business man and Marine veteran who gained national attention as the only openly anti-Trump Republican in the field, picked up only 3 percent of the vote.
Democrats have not won a statewide race in Texas since 1994. When the seat is filled, Texas’ house delegation will be 23 Republicans and 13 Democrats.
“The Republicans turned out and the Democrats didn’t,” said Cal Jillson, a political science professor at Southern Methodist University in Dallas. “That’s a critical takeaway. The party has to think very systematically about what’s wrong and what they need to change in order to be successful.
Since 1983, Republicans have held seat, in Texas’ Sixth Congressional District, which includes mostly rural areas in three northern Texas counties and a sliver of the nation’s fourth-largest metropolitan region around Dallas, Fort Worth and Arlington.
But growing numbers of Hispanics and African-Americans fueled Democrats’ hopes that they had a strong shot of at least getting into a runoff. Mr. Trump won the district by only 3 points in November. Ms. Sanchez, who grew up in the district and built a strong political organization, was widely portrayed as the lead contender in the field of 10 Democrats.
But in the end, she came up 354 votes short after the Democrats splintered the party’s vote, and Mr. Ellzey nudged her aside for the runoff. Mrs. Wright won 19.2 percent of the vote to Mr. Ellzey’s 13.8 percent. Ms. Sanchez got 13.4 percent of the vote.
The large field may have cost Ms. Sanchez a runoff spot, but in the end Republicans won 62 percent of the vote and Democrats 37 percent, not auspicious numbers for her hopes of winning if she did get in the runoff.
“Democrats have come a long way toward competing in Texas but we still have a way to go,” Ms. Sanchez said in a concession statement on Sunday morning.
She said: “We’ll keep fighting for a healthier, equitable and prosperous Texas and to elect leaders who care about meeting the needs of Texans, although it won’t happen in this district immediately.”
The Republican runoff was already showing signs of being fought along familiar right-of-center turf.
Ms. Wright’s general consultant, Matt Langston, assailed Mr. Ellzey, a former Navy pilot who was endorsed by former Gov. Rick Perry, as “an opportunistic RINO” — a Republican in Name Only.
And one of her prominent supporters, David McIntosh, president of the conservative Club for Growth, which has spent more than $350,000 on mail, social media and texts against Mr. Ellzey’s bid, on Sunday called on the second-place candidate to pull out of the race. He said it was more important for Republicans to unite behind Mrs. Wright’s candidacy in advance of the critical midterm congressional races next year.
“If he wants to unite, stop attacking,” said Craig Murphy, Mr. Ellzey’s spokesman, firmly rebuffing Mr. McIntosh’s proposal. Mr. Murphy also denounced Mr. Langston’s statement against his candidate as “silly and insulting” and described Mr. Ellzey as “a guy who has been under enemy fire eight times.”
The defeat in the special election in some respects evoked the 2020 elections in Texas, when Democrats believed that demographic changes put them in reach of a potential “blue wave” to possibly take over the Republican-controlled state House of Representatives and flip several congressional seats. Instead, the blue wave never washed ashore, and the House remains in Republicans hands by the same margin as before.
The Sixth District was once a Democratic stronghold, until Phil Gramm, formerly a conservative Democrat, switched party affiliations in 1983. The district has been a reliable Republican bastion ever since.
The seat came open in February after Mr. Wright, who had lung cancer, died after he contracted the coronavirus. His wife was an early front-runner to replace him, but her chances of outright victory narrowed after the field grew to 23 candidates: 11 Republicans, 10 Democrats, a Libertarian and an independent.