WASHINGTON — One is a Democrat challenging a senator who may be the most popular Republican in Texas. The other is a Republican scrambling to keep a congressional seat in one of the nation's most narrowly divided districts, in a year of stiff anti-GOP headwinds.

They're an odd couple, Reps. Beto O'Rourke and Will Hurd. And as election season marches on, they've stuck by an alliance based on their joint devotion to bipartisanship, and cemented by a 25-hour road trip livestreamed across the nation.

As sincere devotion to improving civic life and public discourse, it's heartwarming. As political calculus, it's a symbiotic relationship that makes strategists in their own parties a bit uncomfortable.

"Part of the reason that video, as goofy as it was or as boring as some of those portions may be, hit such a chord is ... that civility that we rely on to make this democracy work has been absent," O'Rourke said Wednesday, reminiscing about the 1,600-mile journey from San Antonio to Washington 13 months ago. "In Will, I have found not just a very good friend but a partner. ... We'll vote differently on some significant issues but we will find the common ground."

O'Rourke launched his long-shot bid for U.S. Senate just two weeks after the road trip, and the attention certainly didn't hurt as he aims to topple the universally known and unabashedly conservative Sen. Ted Cruz.

The El Paso Democrat appeared with the San Antonio Republican on Wednesday at a forum hosted by the U.S. Hispanic Chamber of Commerce. They largely echoed each other on the need for free trade, warm relations with Mexico, protection for young immigrants facing deportation under President Donald Trump, and the folly of spending billions to construct a wall along the Southwest border.

O'Rourke called it "inexplicable" that protection for young Dreamers can't even get a vote in the House despite overwhelming bipartisan support. "We have to be willing to have the debate ... and we have to be willing to compromise, which has become the dirtiest of words up here," he said.

He decried the "vitriol, hatred and tribalism" that drives lawmakers to stymie progress in the name of scoring a victory over the other side, even when they largely agree on an issue.

Hurd picked up on the point. He emphasized that there's more bipartisanship than the public imagines, but it's always the drama and friction that attract attention and news coverage.

"The only time we hear things about what's going on in Washington, D.C., is when it's broken," Hurd said.

O'Rourke and Cruz

Cruz throws cold water on his challenger's efforts to portray himself as a post-partisan conciliator.

"He's running hard left. Normally Democrats in Texas at least pretend to go to the center. He's not doing that. He's running like Bernie Sanders," Cruz said Tuesday night in a Sirius XM interview with the right-leaning Breitbart. "He's running in support of socialized medicine and higher taxes and higher regulations. He's running in support of open borders. He's running in support of gun control."

He's also the only Democratic nominee for the Senate anywhere to openly support impeaching Trump.

Rankings released this week by the Lugar Center and Georgetown University's McCourt School of Public Policy show that Hurd was the 49th most bipartisan member of the House last year, out of 438. O'Rourke was 93d. In the 100-member Senate, Cruz ranked 85th, making him one of the most partisan senators in the study.

At the Hispanic chamber breakfast, at a luxury hotel a block from the White House, the paeans to bipartisanship flowed freely.

"There's far more that unites us than divides us," O'Rourke said. "And you know that when you actually spend time with your fellow Americans and don't just read about them on Facebook or hear them described on Fox or MSNBC."

1 / 2Reps. Beto O'Rourke (center) and Will Hurd spoke to the U.S. Hispanic Chamber of Commerce at the Willard Intercontinental Hotel in Washington on April 25, 2018.(Todd J. Gillman / Dallas Morning News) 2 / 2

Hurd echoed the point.

He's been asked often, he said, about how a black politician got elected in a Latino district. "I got out and talked to people," he said. "We all care about the same thing: food on the table, a roof over our head. ... America wants us to disagree without being disagreeable. ... We have to be examples and folks have to demand that in their elected officials."

The road trip

Thirteen months ago, the duo embarked on an unusual road trip.

An East Coast blizzard brought flights to a halt. So they rented a Chevrolet Impala and hit the road, heading 1,600 miles back to Washington from San Antonio, and livestreaming the 25-hour journey as an online town hall.

They talked politics, policy and sports. They sang Willie Nelson's "On the Road Again." They shared junk food. They took calls from the likes of Newt Gingrich and answered questions posed on Facebook Live.

Their #CongressionalCannonballRun drew national attention. Facebook founder Mark Zuckerberg approvingly took note of their use of his platform.

As political stunts go — even impromptu ones like this — it was a win-win for O'Rourke, 45, and Hurd, 40, though not a happy moment for their own parties, or their opponents.

Hurd's embrace of O'Rourke complicates Cruz's mission to paint the Democrat as a Bernie Sanders-style liberal. O'Rourke's embrace of Hurd makes it harder for Democrats to tar Hurd with perceived sins of the GOP leadership and Trump.

Cruz has partnered with Democrats on a handful of issues such as military justice reform, but no one would confuse him for a centrist. Mainly, the senator pitches himself to voters as a bridge between the party's conservative and establishment wings, and someone who can work with GOP leadership and the White House.

The alliance has similar benefits for O'Rourke, elevating his profile and drawing a potentially valuable stylistic contrast.

Hurd faces a tough re-election in a district that's divided almost evenly between the two parties. He has always projected a moderate, temperate, thoughtful image — distancing himself more than most Republicans from Trump on border security and immigration.

"Building a 30-foot-high concrete wall that takes four hours to penetrate is the most expensive and least effective way to do it," Hurd said Wednesday, reiterating his view that Trump's approach to border security is off-base.

In November, Hurd will face the winner of the Democrats' May 22 primary runoff: Gina Ortiz Jones, who would be Texas' first lesbian, first Iraq war veteran, and first Filipina-American in Congress, or Rick Treviño, a high school history and geography teacher in San Antonio.

"My experience is crisscrossing 29 counties [in a district] that's 50-50 and it's the size of the state of Georgia. There's way more that unites us," said Hurd, but "if you only talk about wedge issues then yeah, people see that divide."