DALLAS—On an October Saturday morning in a quiet, residential north Dallas neighborhood, one of the most powerful elected Republicans in Washington was wearing a neon-green raincoat, cargo pants, and hiking shoes while holding a half-eaten breakfast burrito on one of his supporter’s lawns. About 50 or so staff and volunteers had joined Texas Rep. Pete Sessions on this gray morning at a kickoff event for “block-walking,” known in most other parts of the country as “canvassing.” The congressman, whom some supporters call “Uncle Pete,” was imploring the assembled to help save his political career from sudden peril.

He urged everyone, first, to wave hello at the tracker from the Texas Democratic Party, who was filming him from across the street.

“We’re gonna let them know that we’re gonna sell the fight,” he said. “We’re not gonna sit back and take this.”

The “this” that they’re not going to sit back and take includes Democrats “distorting the airwaves,” in Sessions’ words, with millions of dollars’ worth of attacks about how he’s voted to eliminate protections for pre-existing conditions and would pursue cuts to Social Security and Medicare. Democrats, Sessions said, want to “move us back to 1.2 percent GDP growth” and also “want to make 13 million illegals legal overnight,” which he argued would be the true long-term threat to Social Security’s health.

For 11 terms, Sessions has been the epitome of an establishment Republican. A conservative but not an ideological crusader, Sessions went to Washington to hold power, raise money, and help business. For years, his only true challenges came from Tea Party activists to his right. But in the scrambled politics of the Trump era, he’s found himself the epitome of another new trope: the endangered suburban Republican.

Across the country, relatively well-off suburban districts that were once the bedrock of the Republican coalition have started to turn. This is especially pronounced in the Northeast, but it’s also taking root in the inner suburban rings of growing metropolises in North Carolina, Georgia, and Texas. Unlike the perennially endangered Republicans in New York or New Jersey, though, this is a completely new world for the Southern representatives whose districts had little Democratic infrastructure until, well, now. The 2016 election was suburban Republicans’ wake-up call, and now they’re scrambling.

As a former chairman of the National Republican Congressional Committee, Sessions—now the chairman of the House Rules Committee, which determines what legislation, under what circumstances, reaches the floor—is used to being the one dressing down Republicans to get their houses in order: to raise enough money, to stay active in their districts, to “sell the fight” and not allow attacks to go unanswered. Now, due to shifting demographics in this north Dallas County district that Hillary Clinton carried in 2016, he’s the one being hunted. Millions have been spent against him or in support of his Democratic challenger, Colin Allred, drawing the race to a coin flip. He labels himself Democrats’ “top target” this cycle. (He’s certainly one of the top three dozen or so targets, but viewing himself as the single top target probably allows him to save some pride, of which he has a lot.)

Unlike the perennially endangered Republicans in New York or New Jersey, this is a completely new world for Southern representatives.

It can be difficult to tell whether Sessions is mad, or happy, or indifferent, or miserable. In speaking to the press, he has one mannerism: flat, but delivered with conviction, regardless of the question he’s been asked. Ahead of this Saturday canvas, though, he did seem mad. It’s one thing when you, as chairman of a campaign committee, are advising others on how to respond to a wave of well-financed Democratic attacks. It’s a different thing when those attacks are hitting you.

“It’s not pleasant for our family,” he said. “It’s not pleasant for my friends.”

“They are shameless,” Sessions later said of the Democrats, talking about how they have, in his mind, twisted his health care position. “They are shameless.”

Texas’ 32nd District was drawn to elect Republicans in perpetuity. But things change.

The district begins just north of downtown Dallas and stretches upward through the affluent Park Cities—Highland Park and University Park—and Preston Hollow. Former President George W. Bush resides in this part of the city, and it includes Southern Methodist University, home of GWB’s presidential library. Much of the district’s northern boundary is the northern boundary of Dallas County, and it bends east to include the suburbs of Richardson and Garland.* An electorate of white, middle-class, suburban professionals kept the district safely red for cycle after cycle, with Sessions rarely facing a meaningful Democratic challenge.

But, as is the case in so many of the contested districts this cycle, the suburban gerrymander has begun to rot as its composition changes. In the 32nd, a growing Hispanic population and an influx of transplants to this booming metropolitan area have created a swing district underneath the 11-term incumbent’s feet.

“The district was drawn now eight years ago, and was more efficient in producing Republican outcomes at the beginning of that time period than it is today,” Cal Jillson, a political science professor and Texas politics expert at SMU, told me. “That’s the case with redistricting all over the country. The lines are drawn for explicit partisan purposes, and they just become less efficient as new people move into the district.”

New people like the “relatively wealthy Anglos moving into the Park Cities,” Jillson said, who don’t share the leanings of some of the more affluent whites who already live there, and don’t vote loyally Republican.

“If they’re coming from Illinois, they’re not dyed-in-the-wool Republicans to the same extent,” Jillson said. “Even a Republican from Illinois is going to roll his eyes at some local Republicans until he gets his bearings.”

Colin Allred, the Democratic candidate, is not a transplant. He’s from the district, where his mother was a teacher. But the demographic changes could finally be enough to put a Democrat over the top in a district that’s only had one representative, a Republican, since its creation following the 2000 census.

“The community I know hasn’t had representation in a very long time, and has been looking for something to change,” Allred told me at an interview in his Richardson office. “The ability to get that done hasn’t always been there. But it is now.”

Allred, 35, has a sparkling résumé in a cycle loaded with sparkling Democratic résumés. After graduating from Baylor, he spent four years as an NFL linebacker with the Tennessee Titans before getting his law degree. From there, he served under Julian Castro in the Obama administration’s Department of Housing and Urban Development before working as a civil rights attorney in private practice. The Texas Legislature’s persistent voting restrictions kept his hands full.

But unlike the state’s biggest Democratic sensation of the cycle, Texas Senate candidate Beto O’Rourke, Allred doesn’t speak in the emphatic, prophetic style that’s mobilized millions—and, by the way, will help Democratic candidates for lower office in metropolitan areas. He’s calm and matter-of-fact, and seemed mildly annoyed when I asked my mildly annoying national-reporter fly-in questions about demographic trends, Hispanic turnout, the existence of a “Kavanaugh bump,” Nancy Pelosi, and so on.

Allred ran to the left in his primary, marketing himself as the most progressive candidate in the seven-person field. He won in a May runoff and has since tried to come back to the center for the general election in what is, still, a traditionally Republican district. When I asked him what policy agenda he thought Democrats should pursue if they take the majority, he became enthusiastic on the issue of infrastructure. Having spent hours in Dallas traffic over the course of a couple of days, I was uncharacteristically eager to hear his thoughts on this bloodless issue. “We’re one of the most rapidly growing areas in the country,” he said. “Our growth is not going anywhere. We need that investment. I think the president would sign it if we put it on his desk.”

Emphasizing pragmatic issues like infrastructure in a general election, rather than Medicare for all, is Allred’s effort to persuade at least some Republicans to vote for him. Though the growth in the minority and transplant populations has made the race competitive, there’s still some doubt on both sides that enough of the district’s traditional Republican voters, even within the swing demographic du jour of “white suburban women who think Donald Trump is gross,” could bring themselves to send a Democrat to Congress.

When Hillary won the district, it was a wake-up call not just to Republicans but to Democrats: Never let Sessions skate by easily again.

“In 2016, [Trump] was of concern to many comfortable, well-educated white suburban women, but at the end of the day, they almost all voted their tax bracket,” Jillson told me. “We’re two years further down the road, and Trump continues to be Trump, and so it’s possible that some of them will change jerseys, as you say. But I think not many.” This is, after all, still Texas.

“White suburban women on the Main Line north of Philadelphia are different than white suburban women in Highland Park, Dallas,” he said.

Missy Shorey, the chair of the Dallas County Republican Party, finds the concerns about the district turning blue because it went Democratic in one abnormal election overblown.

“They gave her a shot,” she told me of the Clinton voters in the district. But, she says, “it’s very important to get this math: I love it when people think that somehow Pete Sessions is not going to win because Hillary Clinton won—Pete Sessions had an additional 30,000 votes over what Hillary secured.” Meaning, there were a lot of people who didn’t want to vote for Trump but did vote for Sessions. He has a cushion.

Still, it’s worth noting that Sessions didn’t have a Democratic opponent in 2016 and had to scratch out his 71 percent against the Green and Libertarian candidates. That wasn’t a mistake Democrats would repeat. When Hillary won the district, it was a wake-up call not just to Republicans but to Democrats: Never let Sessions skate by easily again.

“We were really going to push it,” Carol Donovan, the chair of the Dallas County Democratic Party, told me at a fish fry one Friday night in October, where Allred was the keynote speaker. “And we have, in fact, really pushed it. Not only because we saw that opportunity, where more and more Democrats were moving into that area … but it was also very encouraging to have somebody like Colin Allred, who we knew we could sell to people.”

In his speech, Allred mocked Sessions for only recently introducing a nonbinding “sense of the House” resolution expressing support for protections for those with pre-existing conditions, after voting dozens of times to repeal Obamacare, and criticized him for voting for an “irresponsible” tax bill to be paid for with cuts to Social Security and Medicare.

“The cavalry is on its way,” Allred told the crowd. “The only news is: You are the cavalry.”

Eventually, after having a lengthy conversation with just about every volunteer who showed up, Pete Sessions did some block-walking himself. It was an odd scene as Sessions moved with a small caravan, the House Rules Committee chairman walking a residential stretch of north Dallas with his chief of staff, another aide, four reporters—three from national outlets—and that tracker from the Texas Democratic Party, recording it all. It freaked out some of the residents when they opened their doors to find Pete Sessions with a small press conference in tow.

“I’m Pete Sessions,” he would say. “I’m your congressman.” He skipped a number of houses with Beto signs in their front yards; some people didn’t answer their doors; others pledged their votes for him. One was a confused babysitter. There weren’t any outright rejections, but typically when politicians invite reporters to “block-walk” with them, their staffs select low-risk blocks.

Sessions is much warmer with his constituents than he is with the press. He straddles the line between charming and flirtatious. At one point, two women came up to him to say that they supported him, and one noted that “we met one time in Aspen.” He grabbed her by the hand and had her knock the next door with him. After speaking with a man at one house, he walked back to the sidewalk to brief his blond chief of staff. He asked, “Who’s the blonde out there?”

Sessions and his staff repeatedly emphasized how ingrained “Uncle Pete” is in the community: Everyone knows him; some young people have known him their whole lives. He’s always checking in on his constituents, seein’ what’s up.

This may be true, but the emphasis on community outreach and constituent services this cycle is also a counter to the impression that Sessions’ attention has been elsewhere. “Pete has lost a little bit of traction in the district because he has been in Washington for a long time,” Jillson told me. “He’s become very influential in Congress, as chairman of the Rules Committee, and that simply means that, in terms of his mental effort and time, he focuses on Washington and congressional leadership more than he did 15 years ago, when he was back in the district every weekend, meeting with the Kiwanis and the Rotary.”

After a few blocks, Sessions turned to the press and said, “Did you get what you needed?” This is how candidates politely tell reporters that it’s time to go away. He would continue block-walking by himself, and then he had a wedding to go to that night. He was scheduled to debate Allred the following day, but didn’t seem too nervous about it, or that interested in debate prep.

They do try to prep him, his chief of staff said, “but then he says, ‘I know what I’m doing. I’m gonna have a grilled cheese.’

“Pete’s going to be Pete,” she said.

Election Day will reveal how much longer he’s going to be Uncle Pete, congressman from Texas.

Correction, Nov. 2, 2018: This piece originally said Texas’ 32nd Congressional District bends west into the Dallas suburbs. It bends east into those suburbs.