PALMDALE, Calif. — While walking into Target here recently, Bob and Deidre Murphy noted that Republican Rep. Steve Knight’s 25th District is “a little pocket” of conservatism in Los Angeles County.

“I think that’s going away though,” Bob said. Deidre added, “It is.”

Shifts in demographics and political affiliations have Democrats optimistic they can unseat Knight in a district once considered a GOP stronghold. It’s emblematic of other Democratic targets this year — a suburban seat that Hillary Clinton carried in 2016 with an increasingly diverse population.

Some operatives in both parties say the changing dynamics and Knight’s recent fundraising numbers possibly  make him the most vulnerable Republican incumbent in the Golden State, especially after GOP Reps. Darrell Issa and Ed Royce decided to retire.

Knight disputes that.

“In the last election everybody was writing that I wasn’t going to win. In the previous one, everyone was writing that I wasn’t going to win,” Knight said at the Simi Valley Cajun & Blues Music Festival last week. “I’m always in the district. I flew back across this country 70 — seven zero — times last year.”

“People know me,” he continued. “That’s really hard to beat.”

People like Bob and Deidre.

They’re Republicans who are not fans of President Donald Trump’s style, but they’re supporting Knight. The couple said they know Knight and his wife personally from their children’s soccer team.

Knight acknowledged the increased energy on the Democratic side, but said he plans to keep the focus on his work in Congress and issues affecting the district.

But ahead of Tuesday’s primary, Democrats in the area have a renewed sense of optimism about flipping the seat after voters here backed Clinton. Case in point: an office building in Newhall.

On Saturday, local Democrats opened the office for volunteers to gather and organize. It’s the first time they’ve had an office space during a midterm election year.

Michelle Kampbell, a local Democratic leader, noted at the opening that the space used to be the local GOP headquarters, drawing cheers from the Democrats in the room. Watch: California’s 25th District Diverse in Candidates, Constituents and Land

A changing district

The Knight name is well-known in the 25th District, which encompasses northern Los Angeles County and parts of Ventura County. His father was a record-breaking Air Force test pilot and state senator. Knight worked as a Los Angeles police officer before being elected to the Palmdale City Council in 2004. He went on to serve in state Legislature for six years, and was elected to Congress in 2014.

Residents of the 25th and operatives watching the race noted the district has shifted to the left due to a population boom, with some Democrats pointing to 2016 as a tipping point. Knight won re-election by 6 points, but Clinton carried the seat by 7 points.

“We would set up a headquarters when we could afford to, but nothing like this,” said Diane Trautman, who ran unsuccessfully for the seat against GOP Rep. Howard “Buck” McKeon in 1996 and attended the Newhall office opening last week. “Really, the 2016 election and Trump’s election exploded the energy here.”

Democrats now outnumber registered Republicans in the district by nearly 14,000 voters. Nearly one in four voters are not registered with any party. 

Democrats also see opportunity in the district’s increasing diversity — especially the rise in Latino and African-American residents. Nearly 40 percent of the district is Latino, which makes immigration a top issue.

Knight has signed on to a discharge petition to force a vote on immigration measures in the House. He said he knows the arduous immigration process first-hand since his wife is a Chilean immigrant. But Democrats say the congressman has not done enough to differentiate himself from Trump on the issue.

Democrats are also heartened by activism among younger voters. Last Saturday, shortly before Knight attended the music festival 60 miles away, students marched through Palmdale in the Antelope Valley to call for action on gun violence. Earlier this month, a 14-year-old male student opened fire at Highland High School in Palmdale, injuring one student.

Gun violence remains a top issue, and has become a contentious one among the Democrats competing to take on Knight. Under California’s primary system, all candidates run on the same ballot with the top two vote-getters advancing to November, regardless of party. 

What kind of Democrat?

As the only Republican in the race, Knight is a sure bet to make the general election. But voters will decide Tuesday which Democrat will take him on, and there’s a divide over what kind of Democrat is the best fit for the district.

Katie Hill, an executive at a nonprofit combating homelessness, described the 25th as a purple district, emphasizing she would work with Republicans and Democrats to get things done in Congress.

Lawyer Bryan Caforio, who unsuccessfully challenged Knight in 2016, said the district needs a strident Democrat who is willing to stand up to Trump.

Volcanologist Jess Phoenix also touted her liberal values, but said she wants to focus on the local economy as the area has shifted from one dominated by commuters to one with more jobs based in the district.

Hill and Caforio are viewed as the top two contenders; Phoenix disputes that, saying the analysis is only based on fundraising numbers.

Hill has raised $1.4 million throughout her campaign compared to Caforio’s $1.1 million and Phoenix’s $456,000. Hill also outraised Knight the last two fundraising quarters, which drew some concerns among Republicans about the incumbent’s campaign.

Knight said he has been approached about those concerns, and his improved fundraising will be reflected in the next report. He also noted he will have a cash-on-hand advantage after the costly Democratic primary.

Voters deciding between the Democrats are weighing their policies and also their chances of unseating Knight.

Paul Chandler, a 72-year-old Democrat who attended the Simi Valley music festival, said he was leaning toward Hill since Caforio had a shot at Knight in 2016 and lost.

Caforio explained his 2016 loss saying he only ran a 10-month campaign that he was able to make competitive despite being a political unknown. He noted the Democratic Congressional Campaign Committee didn’t even list the district as an initial 2016 target. This cycle, the DCCC has a field organizer on the ground and has run digital ads encouraging voter registration.

Caforio said he started his second campaign earlier, with a focus on his ground game and reaching out to different areas of the district. That was on display last Saturday in Santa Clarita, where Caforio was canvassing with his wife and a Spanish-speaking volunteer.

A man in a white car called out to Caforio from the street, recognizing him from his campaign ads.

“I think you are the first politician that’s ever come across the railroad tracks,” the man said, referring to the tracks between the neighborhood and the rest of the city.

Caforio said that when he knocks on doors, the top concern he hears is related to Trump. But Hill said she hears more concerns about the economy and health care affordability than comments about the president.

The two have taken different approaches to Trump in their campaigns.

“I think we have to fight his policies and bring voice to those,” Hill said. “But I don’t think we want to make this election about Donald Trump.”

Caforio called the president a “huge issue.” He said people in the community, particularly immigrant families, are frightened for the future.

On some policy issues, the two are in sync. Both support an assault weapons ban. But Hill has also noted that she is a gun owner, saying at a recent town hall that new laws might not have prevented gun-related deaths in her own life.

Both support a path to citizenship for so-called Dreamers, or undocumented immigrants brought to the U.S. as children. Caforio said Democrats in Congress should have used their leverage over government funding to push for a clean bill addressing the Dreamers. But Hill supports a solution for the childhood immigrants that couples increasing funds for border security.

“If you are a Democrat who’s upset that we haven’t protected the Dreamers yet, it’s because Democrats like that have gotten elected,” Caforio said of Hill.

Republicans on defense

Republicans are already gearing up to defend Knight. The National Republican Campaign Committee hit Caforio early, launching a digital ad last August that targeted his position on single-payer health care. (Caforio supports Medicare-for-all legislation.)

And the Congressional Leadership Fund, a super PAC aligned with House GOP leadership, opened a field office in the district a year ago.

“CLF is committed to working to ensure Republicans keep the House, and California’s 25th Congressional District is going to be an important seat to maintaining the majority,” group spokesman Michael Byerly said.

Roughly 50 CLF interns work in the 25th District, and that number is expected to double over the summer to include college students. The group’s office in Lancaster was humming Friday night.

With a snack table stocked with Capri Sun juice pouches and chips, a dozen high school students made phone calls to voters, surveying them on Knight, Trump, the tax overhaul and the initiative to repeal the state’s gas tax increase.

Republicans believe a ballot initiative repealing a recent increase to California’s fuel tax and vehicle fees could drive out voters, especially in the 25th District, which is home to scores who commute in and out of Los Angeles every day. The group is also touting Knight’s work on veterans issues and his support for the GOP tax overhaul (which Democrats say will have a negative impact on Californians).

CLF has a message similar to Knight’s: keeping the focus on his district amid a tumultuous national political environment.

“We kind of keep our head down and do our job,” Knight said. “And I think people like that.”

Inside Elections with Nathan L. Gonzales rates the general election race Tilts Republican.