As iconic civil right leader John Lewis looked on, Senate hopeful Beto O'Rourke told voters on Saturday that they would "dishonor" the work of Lewis and others if they don't help move Texas and the nation forward.

"We've got to make sure we honor the sacrifice of everyone who has preceded us here ... those civil rights workers willing to risk their lives, to be beaten within an inch of their lives ... knowing full well that that would land them in the Mississippi State Penitentiary, Parchman, as it did for John Lewis 57 years ago." O'Rourke said during a rally near Fretz Park in North Dallas.

"We dishonor the sacrifice of all who preceded us if we do not stand tall at this moment, if we do not live up to the promise and the potential of this country."

O'Rourke, a congressman from El Paso, it trying to unseat Republican Sen. Ted Cruz and needs a big turnout from North Texas to win.

Lewis, the longtime Democratic congressman from Georgia, was in Dallas to campaign for Colin Allred, a civil rights lawyer and former appointee to the federal Housing and Urban Affairs Department who is running against incumbent Republican Pete Sessions to represent the 32nd Congressional District.

Along with Allred, Lewis is expected to travel to Houston to help Democrat Lizzie Pannill Fletcher in her race against Republican Rep. John Culberson.

Lewis is one of the few remaining major voices of the civil rights era. He was president of the Student Non-Violent Coordinating Committee and worked closely with the Rev. Martin Luther King Jr., the slain civil rights leader.

His presence Saturday, along with Reps. Eddie Bernice Johnson of Dallas and Marc Veasey of Fort Worth, was designed to help Democrats mobilize voters in Dallas County, a critical battleground for Allred and O'Rourke.

Lewis said when he was a boy growing up in the South, he asked his family why accommodations for blacks and whites were separate. He said they told him: "That's the way it is. Don't get in trouble." He would go on to get arrested 40 times protesting segregation.

"It's time for all good people in this state, here in Dallas, to 'get in trouble' and go to the polls," Lewis said. "Vote like you've never voted before. We must do it. We must take our country back. I don't want to go back, I want to go forward."

Lewis said America should come together and move past partisan divisions.

"We're one people," he said. "We all live in the same house, the American house."

Allred, in a close race against Sessions, said Lewis has inspired him.

"Fundamentally what this election is all about is not Democrat versus Republicans," Allred said. "It's not going to be left versus right. This is right versus wrong. We understand that what's going on in Washington is wrong."

Democratic challenger Colin Allred looks at Rep. Pete Sessions (R-Dist. 32) while speaking during a debate bewteen the candidates for the U.S. House of Representatives, Dist., 32. at Temple Shalom in Dallas on Oct. 21, 2018. The debate was moderated by Sam Baker, Senior Editor and host of Morning Edition on KERA 90.1, and sponsored by AJC Dallas, Temple Shalom, and the Jewish/Latino Alliance. (Carly Geraci/The Dallas Morning News) (Carly Geraci / Staff Photographer)

Allred said that in Congress he would fight for affordable health care for all, better public education and good jobs for North Texans. He said Sessions doesn't properly represent the district and is out of step with its needs.

"We may be the vote that decides what happens in our country," Allred said. "The rest of the world is watching us."

Allred, a former NFL player, is expecting his first son.

"I want to hand over a country to my son that's as good as its promise," he said.

For her part, Johnson urged the crowd to vote, saying a larger-than-normal turnout was needed for Democrats to win up and down the ballot.

"We have an opportunity that we've never had before," Johnson said. "It's up to us. We need everybody to vote ... this election could be the beginning of a new day in Texas."

O'Rourke agreed.

"Whatever the challenge we face, I know we are up to the task," O'Rourke said. "We are a match for this moment. We, the people of Texas, are exactly what this country needs right now."