On a steamy Saturday morning, Beto O'Rourke walked the streets of South Dallas looking for votes. He got three Popsicles.

"I've been block walking since 2005, when I first ran for El Paso City Council, and this is the first time I've been offered a Popsicle," a giddy O'Rourke said. "I'm so excited ... I love purple."

O'Rourke, now a congressman from El Paso, is waging a spirited but uphill campaign to unseat incumbent Sen. Ted Cruz. His strategy involves reaching as many Texas voters as possible, including Republicans looking for alternatives in the era of President Donald Trump.

On Saturday, O'Rourke staged a rally in Cooke County, marking a milestone of visiting all of Texas' 254 counties for his campaign. But for all the hoopla over challenging Cruz in GOP strongholds, O'Rourke's most significant campaign stops over the weekend and Monday were in the Dallas area. There, he reached out to the Democratic Party base voters he'll need to fire up for any chance of beating Cruz in November. He hopes those cool treats given to him Saturday will turn into votes in the fall.

"We are 49th in the country in voter turnout," O'Rourke said before walking a block in South Dallas, adding that the dismal ranking was due to voter suppression tactics. "We need everybody in this election."

In a frenetic four-day period, O'Rourke campaigned in Dallas County, with stops in Grand Prairie, Mesquite, a chicken and beer hall in West Dallas, Paul Quinn College and the gritty, historic neighborhood of South Dallas. On Monday, he participated in a criminal justice forum in Dallas.

Dallas County sports hundreds of thousands of Democratic base votes and is a critical cog in O'Rourke's formula to beat Cruz. Running up the totals in this blue county would take the stress off O'Rourke's effort to lure voters in the GOP's suburban and rural strongholds.

"He gets that this is the base that we have to turbocharge in order to have a chance of winning in November," said state Rep. Eric Johnson, who joined O'Rourke at a rally and block walking in South Dallas. "Crossover votes are important, yes. New voters are important, but we don't win if we don't set a turnout record in communities like this."

Urban voters, especially in the core, have different concerns than their suburban and rural neighbors. And as when O'Rourke visited DeSoto earlier this year, national issues were outranked by basic needs like curbing crime, speed bumps, jobs and keeping people out of the prison pipeline.

"There's nothing that's more powerful ... this is as direct as democracy gets," O'Rourke said as he knocked on doors. "Over time, as all of these individual conversations begin to connect, as neighbors begin to talk to each other and say, 'Hey, you know Rep. Johnson was here with this guy Beto,' they're going to know Eric and I were here and that we care."

Johnson agreed.

"As many people as he can humanly touch in person, he's going to win this election," Johnson said.

Mining the base

With white Democratic Party voters, O'Rourke is nearly a household name, speaking to capacity crowds throughout Texas.

But O'Rourke's campaign and crowds don't fully reflect the diversity of the party, and he's pledged to raise his standing with black and Hispanic voters.

A rally Saturday at Opportunity Park in South Dallas was nearly all white, as were the volunteers who hit the neighborhood to knock on doors and sell O'Rourke to potential voters.

Democratic Senate hopeful Beto O'Rourke waves to supporters at Opportunity Park in South Dallas with state Rep. Eric Johnson (left) and state District Judge Staci Williams (right). (Gromer Jeffers Jr.)

The scene at the rally was much different than what O'Rourke and Johnson encountered on their block walk.

While most of the residents recognized Johnson, none of them knew O'Rourke. Several canvassers told The Dallas Morning News that potential voters were not yet familiar with O'Rourke or engaged in the Senate race.

Rod Jones, who lives in Oak Cliff, was mowing when O'Rourke asked for his support.

"I've never heard of him," Jones said. "I'll give him credit. I've never had a Senate candidate come up to me like that, but I don't know him. He's got work to do with the people in areas like this."

Senate candidate Beto O'Rourke, D-El Paso, knocks on doors in South Dallas with state Rep. Eric Johnson, D-Dallas. (Eric Johnson's office)

After talking to Jones, O'Rourke approached Patricia Nealy as she got out of her car. She invited the busy candidate to the upcoming grand opening of her store on Second Avenue, which she said will sell school supplies. Nealy listed economic development and having elected officials help all business owners as top issues.

Pamela Dickinson was unloading groceries when she came upon O'Rourke and Johnson.

She said she was concerned about crime and the lack of speed bumps on her street, and she thanked O'Rourke for the visit.

"Half the time, we don't know who the people are we're voting for," she said.

A man who said his name was Daryl said he was startled by O'Rourke, who he said didn't look like a politician.

"I thought he was a fed," he said. "I was worried. We don't see a lot of politicians around here."

Sheray Hamilton, who gave O'Rourke the Popsicles, said she was also worried about crime and unsavory activity on her street.

But the three-year South Dallas resident, who said she got married Friday, told O'Rourke that residents there have a lot of pride, and their votes should not be taken for granted.

"I love my street," she said. "I love my neighbors."

Hamilton said she would support O'Rourke against Cruz, as did at least two other voters encountered that day.

254-county campaign

While O'Rourke would like to walk Texas blocks every day, the enormous size of the state makes it impractical.

His strategy involves talking to every voter — Republican, Democratic and independent.

That's why his stop Saturday in Cooke County was so important. He's urged Democrats to think beyond a base fight and develop messages that incorporate Republicans and all other Texans.

Cruz has said that O'Rourke's policies are too liberal for Texas, including his support of the Affordable Care Act, a path to citizenship for immigrants in the country without authorization and a vow to vote for the impeachment of Trump.

But O'Rourke sees his campaign as promoting the kitchen-table issues important to the prosperity of all Texans, including jobs and education.

A base fight it will certainly be, but O'Rourke is counting on crossover support.

That's evidenced by his belief that Tarrant County, a reliable Republican stronghold, could determine the outcome of his race against Cruz.

"Tarrant County is going to determine the direction of this state," O'Rourke said recently in Dallas. "I don't want to just do well in Tarrant County. I want to win in Tarrant County."

Like Dallas County, though, it's black and Hispanic voters in the core of Fort Worth who could make the difference.

And O'Rourke acknowledged that a midterm election year, in which Republicans usually vote in higher numbers than Democrats, would be challenging.

"Dallas has so much untapped potential," O'Rourke said. "People have not come into these elections in years past in midterm opportunities. Though there's not a presidential candidate on the ballot, though we don't have contested races in some parts of the country, we're going to have to transcend that and give everyone a reason to be part of this campaign and this election."