Former Texas Rep. Beto O'Rourke gestures after endorsing Democratic presidential candidate former Vice President Joe Biden at a campaign rally Monday in Dallas. Credit: Richard W. Rodriguez | AP

DALLAS — Texas cast a big shadow on Super Tuesday as the red state with a budding blue streak towers over a shrinking 2020 presidential field — and is now where the Democratic Party’s moderate wing has launched a dramatic front against liberal front-runner Bernie Sanders.

More than 2 million people had already voted early in Texas even before polls opened for Tuesday’s primary. And at the last minute, a turning point came at a Texas honkytonk.

A resurgent Joe Biden packed a Dallas rally Monday night standing with former rivals Pete Buttigieg and Amy Klobuchar, both of whom flew to Texas to endorse the former vice president not 24 hours after each ended their foundering campaigns. They were also joined by Beto O’Rourke — the former Texas congressman who called for confiscating assault rifles during his failed run for the White House, and who Biden introduced to thundering applause.

“We need somebody who can bring us together and heal us. We need somebody who can establish the moral authority of the United States,” O’Rourke told the crowd. “We need Joe Biden.”

The urgency ratcheted up an already substantial Texas primary that was primed to say a lot about the state’s fast-changing politics. Public polling in Texas has shown Biden and Sanders near the top, and billionaire Mike Bloomberg’s run as a moderate alternative was also betting high on Tuesday after skipping the early states and spending tens of millions of dollars on television in Texas. Elizabeth Warren has also vowed to press on and her supporters say she’s positioned to nab delegates in Texas.

There’s also more on the line in Texas than the White House.

President Donald Trump gave an endorsement in hopes of rescuing one of the GOP’s few women in Congress, Rep. Kay Granger, who is feeling the heat from a conservative firebrand. A newcomer in the Bush dynasty, Pierce Bush, was trying to win a congressional seat in Houston. For Democrats, a sleepy U.S. Senate race with a dozen candidates appeared heading for a runoff and had no breakout star — raising flags for a party that has called Texas a battleground.

But most at stake now is whether an extraordinary reunion of three of Biden’s former competitors scrambling to unify Democrats can slow down Sanders, the Vermont senator who was positioned to seize a significant delegate lead after Texas and 13 other states voted in primary elections Tuesday. Texas is a bonanza with 228 delegates at stake, second only to California, which also votes Tuesday.

Sanders, a democratic socialist, has raised deep concerns within the party that he is too liberal to beat Trump in November. That angst has particularly spilled into public view in Texas, where Democrats who have been shut out of power for two decades can finally taste a return to relevance.

They need only nine seats this fall to flip the Texas House, a goal that for many Democrats is their top priority.

“The best chance of delivering this state right now is with Biden,” said Austin Mayor Steve Adler, who had originally backed Buttigieg. He said that it was possible that Sanders “could bring out a different electorate, but I think it would make it more difficult.”

But Sanders has shown a foothold in Texas, and his success is emboldening a crop of insurgent challengers on the left, challenging the Democratic playbook that suggests ending GOP dominance requires broad-appeal candidates who can attract more voters. Among them are Jessica Cinseros, 26, who Sanders endorsed and is trying to become the youngest member of Congress in a bid against Rep. Henry Cuellar on the Texas border.

“People are looking for leadership right now,” said Tory Gavito, president and co-founder of Way to Win, a progressive group founded after Trump’s 2016 win. “With the right top of the ticket, and with the right downballot races, Texas is fair game.”

Marla Davy, 49, said she had supported Klobuchar and drove 60 miles from her home in Sherman to watch the Minnesota senator endorse Biden in person.

“I’m all for whatever moderate nominee is there,” Davy said.