Houston has loomed large in Beto O’Rourke’s improbable emergence from El Paso Congressman to top tier Democratic challenger for the White House.

It was the site of the most viral moment of his 2018 U.S. Senate campaign and the place where he found his answer to criticism over his 1998 DWI arrest. Houston shaped his views on major public policy issues like climate change and criminal justice.

And O’Rourke makes references to Houston and Harris County at nearly every stop as he ping-pongs through early presidential primary states like Iowa, New Hampshire and South Carolina.

Given all that, it was no surprise that O’Rourke, 46, decided to make Houston a part of his 3-city Texas launch of his presidential campaign on Saturday. Hours after holding a massive street party in El Paso formally kicking off his campaign with his family by his side, O’Rourke flew to Houston to pay homage to Texas’s biggest city and an area that turned out to vote in massive numbers in his U.S. Senate campaign for him. Later he was expected to finish in Austin.

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“Huge honor for us to be back here with you in this community that means so much to us personally,” O’Rourke told thousands of people in front of the Martin Luther King Jr. Humanities Center at Texas Southern University.

O’Rourke told the crowd that he has found answers to some of the state and nation’s biggest problems through Houston and its examples of diversity.

“There’s nothing wrong with this country right now, that we cannot make right with this country right now,” he said to a roar of the audience. “And it’s going to be the people of Texas. It’s going to be the people of Houston, Texas who lead the way.”

In an broad, aspirational speech, O’Rourke said as president he’d push for universal health care, pre-kindergarten for all students, better teacher pay, ending the prohibition on marijuana, improving voting rights laws to make it easier for people to register to vote and cast ballots.

“At this very divided, highly-polarized, hyper-partisan moment, what this country needs is for us to come together,” he said.

O’Rourke is among more than a dozen Democrats who have announced they are running for president in 2020. O’Rourke is one of the few in the race that has never won a statewide office, though he set new fundraising records by raising more than $80 million in his loss to U.S. Sen. Ted Cruz in November.

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While no Texas Democrats has been a serious contender for the White House since 1976, O’Rourke has leaned heavily on his ability to help turn Texas into a more competitive state in 2018 as evidence that he can reach voters that many Democrats have not been able to connect with.

That was on display in much of the last two weeks as O’Rouke began campaigning in parts of Iowa that are often overlooked in presidential races. In those stops, O’Rourke frequently turned to Houston to help explain his positions and views on key issues.

Houston was also a big part of the first 15 minutes of his presidential campaign in Keokuk, Iowa, where he warned that if climate change is not addressed, more cities will be hit by storms like Hurricane Harvey and make people rethink how livable their neighborhoods have become.

A day later, at a stop in Cedar Rapids, he was warning about not taking any voters for granted, talking up his frequent trips to Kashmere Gardens in Houston where he reached out to solid Democratic voters who, he said, are sometimes taken for granted by a party that considers them automatic supporters.

When asked about gun control later, he talked about gun activists he met in Houston and students at Sante Fe High School. In Charleston, South Carolina, he touted the victories of 17 women of color who swept judicial offices in Harris County last year as evidence of the nation embracing diversity. Those women were a key part of his speech on Saturday at Texas Southern University, where many sat in the front row as O’Rourke lauded them for “literally changing the face of criminal justice.”

When asked about all his shout-outs to Bayou City, O’Rourke says Houston is a model of what happens when a community truly embraces its diversity.

“I love doing my best to help tell the story of Houston to the rest of the country, that’s why I keep bringing it up,” O’Rourke said in rural northeast Iowa.

O’Rourke said the city is an example of how diversity benefits a community and is not something to be feared.

The role Houston has played in his political emergence was hard to miss in 2018.

While O’Rourke’s U.S. Senate campaign in 2018 was already shaking up the Texas political establishment for months, it was a moment in Houston in early August that propelled him from a Lone Star State peculiarity to a national figure. During a campaign stop at The Villagio, a wedding venue in West Houston, cameras were rolling when a man asked O’Rourke if he had a problem with NFL players kneeling during the playing of the National Anthem.

O’Rourke answered with an impromptu four-minute speech in which he said he had no issue with NFL players participating in non-violent protest to draw attention to racial disparities in criminal justice. His answer, which highlighted key moments of the Civil Rights Movement, become a viral sensation. After more than 44 million people watched the clip online, national talk show host Ellen DeGeneres brought O’Rourke on her show where tens of millions of more people saw the clip that helped turn O’Rourke into a national figure.

“And so nonviolently, peacefully, while the eyes of this country are watching these games, they take a knee to bring our attention and our focus to this problem to ensure that we fix it,” O’Rourke said in the clip. “That is why they are doing it. And I can think of nothing more American than to peacefully stand up, or take a knee, for your rights, anytime, anywhere, in any place.”

Bayou City key to criminal justice platform

That moment has followed O’Rourke on the presidential trail. In Cedar Rapids, it became an early part of the discussion on a popular podcast where the hosts recounted the moment as a critical part of his Senate campaign, as O’Rourke came within three percentage points of upsetting U.S. Sen. Ted Cruz.

In that same month, O’Rourke was again in Houston when he found himself tackling his own past of having twice been arrested, including for driving while under the influence of alcohol twenty years ago. He said it was touring the Harris County jail with Sheriff Ed Gonzalez that he understood even more about the disparities in the criminal justice system for people who are white versus those who are black.

He said when he was arrested for criminal trespassing 24 years ago, he was able to make bail and not have it haunt him, even after he was arrested for DWI three years later. He said it’s clear there are many Texans who can’t afford the bail and their transgressions - though very similar - result in years of legal and financial problems that upend their lives . O’Rourke is from a politically connected family where his late-father was once the elected El Paso County Judge.

“The chance that I had, and which I have made the most of, is denied to too many of our fellow Texans, particularly those who don’t look like me or have access to the same opportunities that I did,” O’Rourke wrote in an opinion piece he sent to the Houston Chronicle the same day he met with Gonzalez and other criminal justice advocates.

O’Rourke has been even more blunt on the presidential trail: “A lot of it has to do with the fact that I’m a white man.”

O’Rourke’s 1998 DWI continues to come up on the campaign trail . He had just turned 26 when police reports show he was driving drunk at a “high rate of speed” on Interstate 10 in El Paso, not far from the New Mexico border. He lost control of his car and hit a truck, sending his vehicle through the median into the path of oncoming cars. O’Rourke was arrested at the scene and charged with DWI, but completed a court-approved diversion program and had the charges ultimately dismissed.

While O’Rourke has confronted the issue before in races for Congress in El Paso, his addressing the topic more directly during his stop in Houston was the first time many statewide voters heard him take on his past, which he called “a serious mistake for which there is no excuse.”

But Republicans have continued to use O’Rourke’s mug shot from that arrest as an attack item. Over St. Patrick’s Day weekend, the Republican National Committee posted a doctored mug shot of O’Rourke on social media while he campaigned in Iowa. The picture included O’Rourke with an image of a leprechaun hat on his head.

The impact of O’Rourke’s Harris County visit can be seen in his presidential platform. O’Rourke has released a position paper on criminal justice that calls for ending the cash-bail system that he says keeps poor people locked behind bars while more affluent offenders get to go home and resume their lives. He’s also advocated for ending mandatory minimum sentences for drug offenses and supporting more meaningful re-entry programs for people who leave jail or prison so they can have a better shot at resuming their lives.

Teenaged activist influenced gun policy

Throughout his first month on the presidential campaign trail, O’Rourke has frequently cited not only the Sante Fe High School shooting but also his meetings with other anti-gun violence advocates in Houston like Marcel McClinton, a high school senior who co-organized Houston’s March for Our Lives.

McClinton, who is running for the Houston city council, was 14 when a gunman went on a rampage in west Houston in 2016. McClinton helped shelter younger children in a Sunday school as one person was killed and several others were injured in the neighborhood. .

O’Rourke in stops in Iowa said that McClinton’s experience reminds him that there are dozens of mass shootings each year that are not followed by national shock and grief.

“There are people in America who are killed every single day who don’t even make the paper or the news,” O’Rourke said, a warning sign that too many people have become numb to the violence.

It’s a big reason he said he’s backing universal background checks and is calling for the end of selling what he calls “weapons of war.” O’Rourke said he supports people being able to still possess AR-15s, but said they shouldn’t be sold anymore.

While the city and county have played a major role in helping him develop public policy positions, it also, he said, offers him a preview of the path to the White House in 2020. He said the record voter turnout in Houston and particularly among young voters was critical to his close contest with Cruz and changing the politics of Texas. He said those victories down ballot for Congress, the state legislature and judicial races give him hope that during 2020 more change is coming at the ballot box.

“You in 2018 gave us a preview of what democracy in this country can look like,” O’Rourke said.