Transcript for How Ted Cruz, Beto O'Rourke are battling it out in heated Texas Senate race
Reporter: Tonight is a moment many thought would never happen, president trump taking the stage with his former foe, senator Ted Cruz. God bless Texas! And god bless president Donald Trump. Reporter: He's come to Texas, a longtime Republican strong hold. Vote for Ted Cruz. Reporter: To shore up support in a state where Democrats seem to be gaining ground. Ted's opponent in this Vass stone-cold phony. Beto O'rourke in this state is running to the left of Elizabeth Warren, to the left of Bernie Sanders, and the state of Texas is not going to stand for it. Reporter: Here the senate race between Cruz and rising democratic star Beto O'rourke is so consequential and surprisingly close. We will find enough common grounds to make things better. We are going to win this race. Reporter: Texas is a deeply red state, but it's changing and change fast. It sits there as a big red target for Democrat. They recognize that if they can start to flip Texas, it changes the entire nationwide electoral map. Reporter: With the mid-term election just weeks away, we traveled to the lone star state to go behind the scenes with both campaigns as they race to the finish line. Do you have any energy? Front and center in this state, imsglags what if we the people of Texas were to reright, for example, our immigration laws in our own image and in our own images. Do we want to secure our borders and keep our communities and families safe? Reporter: In recent days trump announced he's considering militarization of the border. Yes or no, do you support militarizing the border? Militarizing is a politically charged room. We need to deploy whatever resources are necessary. Reporter: That's a yes. If you have a caravan of thousands of people pledging to violate the laws and cross here illegally, of course we should do whatever is necessary. Reporter: Congressman O'rourke sees things differently. He grew up in the border town of El Paso and speaks fluent Spanish. You say you want to secure the borders. Can you do that without a wall? Can you do that without militarizing the border? We don't need a wall to answer the question. We don't need to militarize the border f.things are so desperate in Guatemala, Honduras, el Salvador that someone would risk their lives to come here, then what can we do to improve conditions there? Reporter: His stance on immigration is not the only thing going against the grain in this state that's been red for decades. You're pro gun control and pro immigration and pro choice and pro pot. I may characterize the positions you described a little differently but what I'll tell you in each of them I found the common ground in the state of Texas. These are human value tds, American values and Texan values. Reporter: Are they too Progressive for Texas? No. Reporter: O'rourke's campaign strategy is to appeal to the common man and has made an effort to travel to every county in the state. Just human beings, real people making this happen. Reporter: And expanded his brand nationally through social media, live streaming everything. Reporter: And it's worked. He's raised an extra $38 million in the last three months. So we're backstage getting ready to talk to the man that is captured Texas and the entire country. How do you translate the momentum into turnout? So you show up everywhere. We -- we have one of the most simple obvious strategies that I've seen employed in a modern campaign. We just literally show up everywhere all the time for everyone. Reporter: Cruz has opened up a bit of a wider lead, but everyone attached to the campaign knows it is a potentially soft lead. Reporter: For senator Ted Cruz his campaign strategy, deeply Texas. So this is a legitimate stockyard where we are getting ready to witness this Ted Cruz rally. I don't even know what the heck that is. I love him because of his record. He fought for our religious liberty and second amendment rights. Reporter: One of the St. Super supporters Maggie Wright has followed Cruz for years, even moving to Iowa during his presidential run. Is there a more fanatical supporter senator. No, for my 50th birthday my husband wanted to know what I wanted. Reporter: I'm afraid to hear what you said. I want Ted Cruz for president. Reporter: He lost that race and now he's aligning himself with the man who won to the surprise of many. I'm proud to work hand in hand with president trump. Reporter: You have said terrible things about each other. He's a pathological liar. Lyin' Ted. You're a sniffling coward and lev Heidi alone. Reporter: Are those things not true? I have no interest in revisiting the comments of 2016. Reporter: You've moved on. I've got a job to do. Reporter: And the president cozying up as well. He's not lyin' Ted anymore. He's beautiful Ted. I call him Texas Ted. Reporter: Is he your friend or foe? How do you describe the relationship? He oats president and I work with the president in delivering on our promises. Reporter: Cruz touts his track record to galvanize the vote. They need to go out and vote. Texas is booming, the economy is going great and yet my opponent, Beto O'rourke, he wants higher taxes, higher regulation and go back to the Obama economy stagnation. That would be really bad for the state of Texas. Reporter: Last week his opponent took a page out of Donald Trump's playbook, even though O'rourke has vowed to run a positive campaign. He's dishonest. That's why the president called him lying Ted and why the nickname stuck because it's true. That wasn't the best phrase for me to use. Something that leapt to mind as he began the debate with another lie, and there you go. I'm going to do my best to stay focused on the future. Reporter: And part of that focus is in attracting minority voters. I look at Beto O'rourke, and it seems like he has a feel and a love and a need to help all people, not just a select group. As a first generation Mexican, mexican-american now, a mother and a teacher, he stands for the values that I stand for. The idea that Texas is ripe for the picking, it's powered by the growing minority population, the growing young voter population. It's almost inevitable that Texas turns blue. The question is did Beto O'rourke find this moment? Reporter: This race is still up for grabs, and in the current political climate not everyone is voting down party lines. You all classify yourself as evangelical. How many of you plan on voting for Ted Cruz? Crickets. How many of you plan on voting for Beto O'rourke? Me. Reporter: And for most of these women this is the first time they will be voting for a Democrat. For so long the foregone conclusion was the Republicans would get the evangelical vote. I think what we've seen happening is the -- is the systematic oppression of people of color, of people who are seeking asylum, of refugees, of -- of women, and it feels like a lot that have is coming from the Republican party. Reporter: At this point what Beto done to earn your vote? Given me a broader option. He has said I'm going to work on both side. He said I'm not running like for the democratic party. I'm running for the people. Reporter: Cruz's supporters see their votes as value-based, foo. Thank you and god bless you. Big fan of Ted Cruz, everything he stands for, and I think the less government intervention, the better. We're sticking with our conservative values and supporting Ted Cruz all the way. Reporter: With early voting beginning today, the stakes are only getting higher as we wait to find out if this red state will turn blue. For "Nightline" I'm Paula ferris in Dallas.
This transcript has been automatically generated and may not be 100% accurate.