Elise Stefanik was worried about chocolate milk.

Stefanik, a Republican congresswoman representing much of northern New York state, sounded a clarion call on 4 March that New York City – perceived by many rightwingers as a hotbed of leftist depravity – was trying to cancel a wholesome children’s beverage.

“Rather than going after violent criminals, New York City’s Mayor Eric Adams is prioritizing banning chocolate milk from NYC’s public schools,” Stefanik said on Twitter.

No matter that Adams hadn’t recently made any notable moves to ban the beverage, according to Politico: in the days and weeks that followed, Stefanik would intensify her efforts. While there was an across-the-aisle element in these efforts – Stefanik signed a bipartisan letter expressing valid concerns about cutting kids’ access to a nutritious drink – she used Republican talking points about liberals to publicize this letter.

Stefanik then introduced the Protecting School Milk Choices Act to Congress, which would require that schools participating in the US school lunch program offer pupils a minimum of one flavored milk option.

When Adams abandoned talk of banning chocolate milk in schools, Stefanik transformed this “win” into yet another GOP dog whistle. “Make no mistake, any effort of Mayor Adams to ban chocolate milk and replace it with vegan juice is an absolute non-starter and will be opposed by parents, families, kids, and New Yorkers,” she told the New York Post. During this crusade, Stefanik repeatedly praised her constituents who provided this milk, saying “our dairy farmers work hard to produce nutritious milk for our communities”.

Stefanik’s rhetorical approach to a largely non-partisan belief – lots of people like the idea of kids having milk in school – helps explain her meteoric rise from moderate New York Republican to a potential 2024 vice-presidential contender who has moved increasingly to the right. And unlike her colleagues Congresswoman Marjorie Taylor Greene and Senator Josh Hawley, Stefanik has avoided embarrassing public gaffes, positioning her to become a key architect of the Republican legislative agenda.

In her district, Stefanik appeals to many constituents, from dairy farmers to struggling blue-collar workers, by saying things that suggest she’s actually listening to them. On the national stage, Stefanik has appealed to the Republican base with dogged support for Donald Trump and more moderate Republicans alike, often by using favorite GOP talking points, such as a purported anti-police crime wave and the bogeyman of veganism.

“Where she comes from, up in St Lawrence county, is a rural conservative area, and she is appealing from the standpoint that she is unapologetically conservative – and I think that’s what has brought her quickly to rise in prominence in the Republican party,” said the Republican New York state senator George Borello.

Stefanik, who now bills herself as “ultra-Maga” and “proud of it”, wasn’t always a Trump evangelist. When she won her congressional seat in 2014 – then the youngest woman ever elected to the job, at age 30 – many described Stefanik as a rising star in the party. Indeed, she had the pedigree and political relationships that any Republican politician would envy – a Harvard undergraduate education, a job in the George W Bush White house, and a stint with the 2012 Mitt Romney presidential campaign.

She cast herself as an establishment Republican, eschewing the acerbic rhetoric which, around that time, had made Trump a disliked outlier in his party. “I’m a Republican because I believe in limited government,” she said in a 2015 C-Span interview cited by NPR. “I think Republican principles help the vast majority of all Americans achieve the American dream and I believe in the constitution.”

Stefanik’s early voting record was relatively moderate. Heritage Action for America, a Republican lobbying organization, gave Stefanik a 29% rating on its conservatism “scorecard” for the 2015-2016 session, partly because she voted on legislation that went against her party’s lines, including a measure that provided $170m to tackle the water crisis in Flint, Michigan, and a continuing resolution to fund Planned Parenthood. During the 2017-2018 congressional session, her score dipped to 24%.

Stefanik changed her strategy around November 2019, during the House intelligence committee’s Trump impeachment hearings. “This is the fifth time you have interrupted members of Congress, duly elected members of Congress,” she told the committee chair, Adam Schiff, a Democrat. Stefanik subsequently tweeted: “Adam Schiff flat out REFUSES to let duly elected Members of Congress ask questions to the witness, simply because we are Republicans.” She told Roll Call that barb-trading with Schiff had boosted her re-election campaign, reportedly saying her district was “becoming more Republican”.

“She has this moment that kind of goes viral,” said Shawn J Donahue, an assistant professor at the University of Buffalo’s department of political science. “That was one of the things that helped really get her on a lot of programs on Fox and such. You saw her become a really ardent defender of Trump during the impeachment process.” Her Heritage score increased to 56% in the 2019-2020 session. It’s now at 86%.

Stefanik was ultimately among the Republican lawmakers who backed litigation that attempted to get the US supreme court to overturn President Joe Biden’s win. While she did condemn the violence on January 6, she also voted that evening to reject Biden’s win in Pennsylvania.

Stefanik’s allegiance to Trump paid off in May 2021. House Republicans, weary of the Wyoming representative Liz Cheney’s criticism of Trump, booted Cheney from the role of conference chair. Two days later, they chose Stefanik to replace Cheney – making her the No 3 House Republican.

One year later, Stefanik’s ascent is all the more consequential. She has come out swinging against the House committee investigating the attack on the Capitol.

She has also furthered conspiracy-minded rhetoric, including campaign ads that drew comparisons to the “great replacement theory”, according to the New York Times. This racist and often antisemitic belief, allegedly expressed by the suspect in the mass shooting in Buffalo, New York, in May, holds that the ruling class hopes to “replace” white Americans. (Stefanik’s campaign and office did not respond to multiple requests for an interview with the Guardian.)

When the supreme court ruled last week to overturn New York’s handgun restrictions – and overturned the Roe v Wade decision that granted women the right to abortion in the US – Stefanik celebrated. “While the Far-Left continues to push unconstitutional gun control measures as New York’s failed bail reform policies have made our communities more unsafe, this ruling comes at a crucial time,” she said. Stefanik, whose district is largely rural and pro-gun rights, described herself as a “major supporter of the lawsuit” that prompted the gun ruling.

Stefanik; the House Republican leader, Kevin McCarthy; and the House Republican whip, Steve Scalise, said jointly of the Roe decision: “Every unborn child is precious, extraordinary, and worthy of protection. We applaud this historic ruling, which will save countless innocent lives.”

Stefanik’s seeming transition from traditional Republican to the far right comes as her district appeared to shift more conservative: while Barack Obama won the district in 2008 and 2012, Trump won in 2016 and 2020 with 54% of the vote each time. Less clear, however, is whether this is because the district is actually more Trump-minded – or constituents simply don’t like Democratic policies.

Jon Greenwood, a Stefanik supporter, runs Greenwood Dairy in Potsdam, New York. His black-and-white Holsteins live in spacious barns, where they can eat, lounge and get massages with an electric brushing machine as they please.

“She, to me, seemed like a very bright, energetic candidate who understood small business and wasn’t a big government person and that the answer to all our problems isn’t some new program or new law,” Greenwood said.

Greenwood said that while “I don’t agree with everything that she does”, he believed that she was doing a good job generally. He pointed to Stefanik hosting a phone panel with dairy farmers.

“There were 15 farmers on, maybe more, and she would go around and each one of us would tell what our concerns were, and then we’d have to have, you know, back and forth, but you would make sure that everybody on the call had a chance to have input,” he continued.

“I think more people are interested in the policies than they are in what she says and doesn’t say about Trump.”

Daniel Whitten, who runs Whitten Family Farm in Winthrop, New York, said he was “very likely to support Elise”.

“I don’t think she’s entirely stuck on party lines. I think she looks at things as individual items,” said Whitten, who grew up in a Republican family but describes himself as having a “more libertarian” viewpoint.

On the main thoroughfare of Lake George, a popular tourist town in New York’s Adirondack Mountains, two storefronts beckon would-be customers with a poster of Trump in sunglasses, with the words “The Trumpinator” written above his head. Below, the poster reads “I’ll be back 2024,” a play on Arnold Schwarzenegger’s famous line in the Terminator franchise.

The shops are for William Massry’s clothing brand, Dilligaf, which stands for “Do I look like I give a fuck?” Dilligaf is a general mantra about living freely, said Massry, who described himself as an independent and said he voted for Bill Clinton and Obama, but “my customers are Republican. They love Trump. They think Trump’s walking on water. Trump is God to them, so I target market [to] my customers.”

“I don’t like Trump as an individual. I think he’s ruined the atmosphere. He’s a bully. I don’t like him making fun of handicapped people, which he has done. He, I mean, he has [had] many incidents that embarrassed me to even say he’s our president. However, he’s great for the economy,” Massry said.

“Now, Elise, I don’t think she feels that way. She will do anything for the votes. And it’s got her very far, and God bless her. She’s a politician, much like I’m a businessman. She does what she needs to do to stay in power and rise the ranks.”

While Stefanik and her district have grown more conservative, there remains a contingent of constituents who are less concerned with political horse-trading than they are with just getting by..

At the Veterans of Foreign Wars outpost in Glens Falls, a modest house that serves as a community hall for veterans old and young, Lisa Springer didn’t want to get into partisan discourse. But she was willing to share her concerns on veterans’ issues.

“I think she could do better. OK. I’m not gonna say it’s bad, but you know, she, I think she could do better and just do more, especially as far as advertising is out there,” Springer said. “Some people don’t even know that there’s programs out there that can help them, or where to find them.”

Springer, who runs a trucking company, is feeling economic pressures like so many other Americans. “Ten dollars an hour today isn’t what it was 10 years ago, five years ago. I have three kids. So paying $5 a gallon for gas is definitely robbing the food out of the fridge,” Springer said.

Elsewhere in the district, the Glens Falls resident Andrew Sundberg, 57, is among the disenchanted. Sundberg, a registered Republican, did not vote for Stefanik in the last election, nor will he in the upcoming race.

“Elise is terrible,” he said. “She believes in Trump’s ‘stop the steal’, which did not exist. She’s not the only problem, but she is a problem.”

He surmised that Stefanik enjoyed support in the district because she’s a Trump Republican and supports law enforcement. Unlike some others interviewed, he felt that Republicans in the district were Trump-aligned, not just supportive of party policy.

“I will not vote Republican again after January 6,” he said.

For political insiders, Stefanik’s fast ascent wasn’t expected, but they knew from the get-go that she was the candidate they wanted.

Gerard Kassar, the New York state Conservative party chairman, said the party had endorsed Stefanik early on. “That very effectively assisted her in winning the Republican primary because in many ways, having a conservative line for GOP voters is like a Good Housekeeping seal of approval.

“Did I know at that point someday she would be a potential candidate for speaker? No, I had no idea,” Kassar said. “But I did certainly know that she was the right person to support for Congress.”

“As her time in Congress has moved forward, she’s gone from the center right to really, a clear right-leaning member of Congress, which, in the Conservative party, that’s what we want to see.”