Washington (CNN) When Katie Hill opened the heavy wooden door to her new congressional office in the Longworth House Office Building, one feeling smacked her in the gut.

"Well, this doesn't feel like me," recalled the freshman congresswoman from California's 25th District.

"So yeah, this very formal place being my home base does feel strange," she added. "I don't want to become more formal. That's not on the table."

Hill argues her life doesn't allow her to embrace any of the formal trappings of Washington. Raised in suburban Los Angeles, she prefers sneakers to heels. She's a Democrat and the daughter of a Republican police officer and survived a sexual assault. Socially conscious, she married a man but identifies as bisexual.

The thrust of her career has been in non-profits, as an advocate for the homeless. She also embraces the sexist criticism, known as "resting bitch face," about a serious woman (like her) not smiling while thinking.

This isn't the sort of resume or life story that typically precedes a seat in Congress, but that's just fine with Hill and the voters who elected her. An unconventional woman, the 31-year-old joins the 116th Congress, the most diverse legislature in history by many measures — gender, race and sexual orientation.

Refusing to change is part of the internal feedback loop in Hill's first days in Washington.

Sometimes in the middle of an unreal day, you just really need to hug your mom.



We're about to be sworn in. Let's do this. pic.twitter.com/8zmyMbgvb9 — Rep-elect Katie Hill (@RepKatieHill) January 3, 2019

A grassroots candidate

Hill won with an insurgent campaign spurred by the 2016 election. She channeled her anger at the victory of President Donald Trump by taking aim at her congressman, Rep. Steve Knight, who voted with fellow House Republicans in May 2017 to dismantle the Affordable Care Act. "Who is going to run against him?" Hill typed out on her social media accounts. A friend said, "Why not you?"

Why not, thought Hill.

A year and a half later, Hill flipped the suburban Los Angeles district for Democrats. The first-time candidate had started her grassroots campaign out of a rented apartment backed by a hoodie-wearing millennial staff, chain-sipping La Croix sparkling water. The team raised more than $8 million without taking a cent in corporate or special interest money.

Hill won over voters as a progressive advocate for affordable housing while offering a pragmatic willingness to work across party lines for her purple district. Trying to fit into Washington is not why Hill was elected nor does it sit anywhere on her agenda.

"Playing nice isn't really something that's in my vocabulary," she said. "I just do what I think is right."

Demanding to be heard

That philosophy may sound quaint, even naive, for Washington, but Hill believes that's the shared sentiment among the incoming freshmen congressional class.

A record-setting 127 women were elected to the 116th Congress, the majority of whom are Democrats. More African Americans, Latinos and LGBTQ members now serve in Congress. The legislature also saw its median age drop by approximately a decade with its newly elected members.

Katie Hill laughs as Nancy Pelosi's granddaughter reacts to votes for Pelosi to become Speaker of the House.

Hill is notable for her youth as well as being California's first openly bisexual woman elected to Congress. But it's the sheer size of the freshman class, at 92 new members with 46 flipped seats in the 2018 midterm election, that's politically powerful to her.

Traditionally, new legislators have been expected to wait their turn while more seasoned members drove the agenda. But this time, and in this age, the newbies are demanding their voices be heard.

"I think we have enough power and enough strength in numbers and enough of a strong mandate from voters that we're going to be able to continue to stay true to the things that we ran on," said Hill, who was elected to the Democratic House leadership team as one of two new members representing freshmen.

Katie Hill, right, poses with other members of the newly elected Democratic House Leadership team in November.

The result, she hopes, will be in them governing differently.

A new agenda and attitude

Top of Hill's agenda is focusing on a more equitable system, from health care to taxes to housing. Hill believes the biggest problem with Washington has been the "billionaire class" being controlled by special interest donors and ignoring the needs of the politically powerless.

"We are regular, middle class people," said Hill, the now third-youngest member of Congress (behind Reps. Alexandria Ocasio-Cortez of New York and Iowa's Abby Finkenauer.)

"We're young. We look like and speak like the people that we're there to represent. We're not people who came up through the political process. The majority of us are first-time candidates. We're not stuck in the old way of doing things," she said.

This Freshman class is larger, younger, and more diverse than ever before and that's not a coincidence -- it's a call to action.



Yesterday @JoeNeguse and I were elected to be the Co-Representatives to Leadership for this historic class and we are so ready to get to work. pic.twitter.com/GZv3FUElNe — Katie Hill (@KatieHill4CA) November 29, 2018

Hill spoke to CNN as she made the flight to Washington from Burbank, California, inviting us to chronicle her journey from candidate to congresswoman-elect to swearing in.

A millennial, Hill embraces the sharing philosophy of her generation via social media and speaks easily with reporters as cameras roll. She's shared on Twitter and Facebook her personal stories about surviving sexual assault and an unplanned pregnancy that ended in a miscarriage. In her unconventional political ads, she went rock climbing.

As Hill checked in for the 6:45 a.m. flight, she remarked, "I've never lived outside of California or traveled with so many bags." For the record, there were three suitcases.

She wore athletic clothing for the flight, noticing then, under the bright fluorescent lights of the ticket counter, that her black pants were covered in her dog's white hair. "Oh well," she said, as she walked towards airport security. Her goal, she said, is to demystify Congress by bringing her voters with her on this journey and through her entire term, dog hair and all.

"I think what I, and many of the other freshmen have, what's kind of unique, is this sort of ability to relate to people in a different way."

I left my house in SoCal and it was 37 degrees, landed in DC and it's more than 50 degrees here! What a warm welcome! ☀️



Can't believe inauguration is this week — I'm so ready to get to work. 💪🏼 pic.twitter.com/UV28nRQPFO — Katie Hill (@KatieHill4CA) December 29, 2018

It's why on Hill's Twitter feed she's posted frequent updates on her first impressions of Washington during new member orientation, known as "Congress Camp." She talked about what committees she hoped to join to best represent her district, a sprawling community with suburban middle-class families and lower-income desert communities, and doesn't plan on slowing down the tweets.

'There's going to be fights'

Hill signed the lease at her new home -- a small, no frills, two-bedroom apartment that gives off a corporate, temporary housing sensibility. It's there she caught up with her roommate and fellow freshman, Rep. Lauren Underwood of Illinois. Nearly the same age, the congresswomen initially give off a bubbly vibe of moving into a college dorm.

You can only have tough dinner table conversations if you first get the dinner table! 😂 @LUnderwood630 is the best Ikea partner I could imagine — the true test of roommate compatibility! (And maybe our negotiation skills too...) pic.twitter.com/knACssVjXF — Katie Hill (@KatieHill4CA) December 30, 2018

But as Underwood talked, it became apparent that both carried the weight of their new elected jobs.

"I think it's going to be hard," said Underwood, who also flipped her district, defeating a Republican male incumbent. She is now the youngest black woman to ever serve in Congress. "We don't walk in and everything automatically changes."

"I would imagine there will be confrontations," said Hill. "There's going to be fights between the old guard and the new one. But I feel very optimistic that the existing leadership all want us to be part of this process. They recognize the change that's happening, and they're trying to include us."

The nameplate for Rep. Katie Hill outside her office on Capitol Hill.

On inauguration morning, a crush of cameras greeted Hill, swarming around her as she tried to enter the Capitol to be sworn in.

"It feels good. It feels like we can finally get to work," she said.

She stepped into the US Capitol through the south door entrance and disappeared into the tunnel. Her cross-country journey had ended but her new role as Congresswoman Katie Hill had just begun.