Katie Porter sits inside a Starbucks sipping an iced coffee as a steady stream of customers pass by in the seasonal uniform of shorts and flip-flops, discussing what might have been.

She hadn't intended to spend her summer like this.

Armed with a whiteboard and a marker pen, the Orange County congresswoman has risen from obscurity to political celebrity virtually overnight, criticizing lobbyists, harrumphing CEOs and pestering corporate executives aplenty, much to the delight of Democratic online and cable TV viewers.

She transformed herself from a University of California law professor into a fundraising powerhouse, a progressive heroine and a much-talked-about candidate for high office. But it all came tumbling down when Ms. Porter suffered a crushing defeat in the Senate primary to Rep. Adam B. Schiff. Now, while Mr. Schiff is on track to win election and life tenure in Washington, Ms. Porter is just months away from facing the end of her congressional career.

Porter says she has no regrets.

It's not about how she ran her Senate campaign, or abandoning the national platform she helped build, or abandoning a House seat hotly contested by Republicans after three terms and six years in Washington and at a time when much of her field is still in its infancy.

“What on earth would I want to change?” Porter asked himself, and then answered himself: “A lot of things. A lot of things.”

For example, the war in Gaza has galvanized a peace movement within the Democratic Party and bolstered the candidacy of Rep. Barbara Lee, Porter's main rival against the centrist Schiff for liberal support.

“Do I think I underestimated some factors and overestimated others? Absolutely. Do I think I did the math or the calculations? Yes,” Porter continued, “But looking back at that campaign, I don't think there was one particular moment or one particular decision that dictated the outcome.”

The morning rush had vanished, and an egg and spinach wrap sat uneaten in front of the porter.

She is still hurt by the millions of dollars in negative advertising that was splashed on her by the crypto and tech industries in support of Schiff, but she says her support for her former rival was heartfelt and sincere.

“Adam, Barbara and I remained very close throughout the race,” Porter said. “We saw each other every day at work. People forget that. We sit in delegation meetings together, we fly together. One of the first people I saw after I lost was Barbara Lee's son, and he said, 'That was a great race.' We understand that when you run, someone is going to win and someone is going to lose.”

Her only hope for Schiff is that he will use the fall campaign (against his chosen opponent, hapless Republican Steve Garvey) to talk up some of the many issues facing California.

“We need a real policy debate in California,” Porter said. “California is [Gov. Gavin Newsom’s] “Some people have this golden California dream, and then there's this mentality of, 'This is a failed state. People are leaving.' That's the narrative. … This race was an opportunity to have a real policy debate about our state, and I don't think that happened.”

Blame it on voters' short attention spans. Blame it on a shrinking political press corps. Blame it on a race that failed to captivate most Californians. Blame it on the nuances among largely like-minded Democrats and the lack of a real Republican competitor to stimulate deep, meaningful debate.

With Schiff cruising through the election, Porter said, “I hope Adam will go back to some of the policies that were really important to him in the Senate and talk about housing, the environment, energy, taxes, and really think about, 'What does California want from Washington?'” when he becomes a senator.

One customer, wide-eyed, approached Porter and wished him luck. The 47th Congressional District, which stretches along Orange County's coast, is one of the most competitive congressional races in the country, with Democrat Dave Min and Republican Scott Baugh vying to replace Porter in Congress.

She has few illusions about the organization she is leaving.

Congress is a sluggish, wild beast, deeply polarized and hostile, and Porter said leaders of either major party have little appetite to fix it.

“My colleagues want to have conversations — whether it's Senator Schiff running for Senate, whether it's House candidates, whether it's Vice President Harris, and you'll hear them this fall — they want to go on and on about the crisis of confidence in the Supreme Court,” Porter said. “What about the crisis of confidence in us, in Congress? Who are we serving and how effective are we? That's a conversation worth having, too.”

(There's a reason why former House Speaker Nancy Pelosi, who wielded so much influence over Schiff in the Senate primary, was such a reluctant supporter of Porter.)

For now, Porter is looking forward to returning to the classroom in January to take up her old position at the University of California, Irvine. Her face lights up when she talks about being in front of students again. She will teach a first-year law class and courses on business and legislation.

She has a new Burmese kitten, Dino, and a Basset Hound puppy, Poppy, and as a single mother of three, she happily gives up her grueling commute across the country to Washington and looks forward to her kids coming home from school.

Taking a sip of coffee, another passerby, a woman in a fluorescent green safety vest, greets the porter.

She hasn't ruled out running for statewide office in the future — Porter could be a strong candidate for attorney general or governor — but she's in no rush to make a decision. (By contrast, she was the first to enter the Senate race after the late Sen. Dianne Feinstein announced her intention to retire.)

Porter rebuked about a half-dozen gubernatorial candidates who have already begun their campaigns.

“In my opinion, no one should be campaigning for governor between now and Election Day,” Porter said. Democrats rightly argue that Donald Trump is an existential threat to democracy and that the party must do everything in its power to stop him.

“If that's what you think,” Mr. Porter said, pumping his fist, “that's what we should all be doing now,” instead of jockeying for power in an election that's still more than two years away.

At 50, still on the cusp of youth by modern political standards, Porter still has a long way to go.

She said she remains committed to serving in public life in some capacity.

“I’m not tired of being a candidate at all, I’m not tired of campaigning,” she said, finally turning to her abandoned spinach wrap, “but I don’t know what that’s like, and I’m in no rush.

“I'm going to look for something that feels right, whether that's an elected position, I don't know what level, whether that's in the administration, whether that's a position on some kind of California Civil Service Commission, or maybe a role in the Kamala Harris administration.”

Her short but illustrious congressional career may soon be over, but Porter suggested it's not over yet.