PHILADELPHIA — The hulking, big-hearted mayor of Braddock, Pennsylvania, is not especially welcome in Washington, D.C.

It’s not that the 46-year-old, 6-foot-8 John Fetterman can’t get a meeting with the power brokers in the nation’s capital. But the one he got last year with the Democratic Senatorial Campaign Committee showed that the antipathy is at least somewhat mutual.

“We did talk to the DSCC in D.C.,” Fetterman recalled Friday, sitting outside a donut shop and cafe before taping the final debate of a Democratic Senate primary that features front-running former Rep. Joe Sestak and Katie McGinty, the former chief of staff to Gov. Tom Wolf.

“We talked to them actually for four or five hours, and they were like, ‘Hey, you guys, you know, good with us,’ and ‘We’re staying out of it.’”

But as of last week, the DSCC had spent about $1.5 million on advertising for McGinty.

“They reneged on that promise, clearly, in a big, big way,” Fetterman said. “That’s the only conversation that we’ve had in Washington with the elites or the establishment.”

Fetterman is not especially surprised. He's the sort of outsider whose ideas about inequality and belief in the need for fundamental change have long alarmed cautious, triangulation-prone party leaders who now worry that Bernie Sanders (I-Vt.) is making overly bold promises that he can't possibly deliver. But Fetterman is also exactly the sort of candidate who, if he can win, would give Sanders a better chance of passing things like a $15 minimum wage, universal health care and free public college. And right now, not only are Democratic Party leaders not helping, they're standing in the way.

Keith Srakocic/ASSOCIATED PRESS John Fetterman addresses a crowd on the roof of his home during his announcement that he is running for the U.S. Senate in Braddock, Pennsylvania, Sept. 14, 2015.

The DSCC declined to discuss its conversations with candidates, but the steps the committee has taken show pretty well what its strategists are thinking. With the rise of Donald Trump on the Republican side and the potentially historic election of Hillary Clinton, Washington insiders feel like their best chance to pick off GOP incumbent Sen. Pat Toomey rests with McGinty, an accomplished woman who served in the Clinton administration.

And Fetterman isn't even their top concern in the Pennsylvania primary. They are much more focused on the prickly, advice-averse Sestak, who narrowly lost to Toomey six years ago.

But it’s entirely possible that in shunning Fetterman, they’ve missed a chance to embrace a candidate who better reflects the disruptive mood of 2016 and the anti-establishment fervor that’s propelled the unlikely presidential bids of both Trump and the 74-year-old democratic socialist, Sanders.

McGinty, 52, and Sestak, a 64-year-old former admiral, embody the old Democratic Party that has left younger voters and many others cold, in Fetterman’s view.

“I wanted to be a true progressive option in a race of more centrist and kind of traditional Democrats,” said Fetterman, who has endorsed Sanders.

If Fetterman is anything, it’s non-traditional. After graduating from business school and starting a lucrative career in insurance (his father also had built a successful insurance business in York, Pennsylvania), personal tragedy prompted Fetterman to reconsider his life's path.

One day when he was 23, Fetterman waited for his best friend to pick him up for a workout. His friend died in a car crash on the way there. The resulting introspection led Fetterman to wonder why he had been so fortunate, compared to others, and to look for ways to spread some of that good fortune around.

Big Brothers Big Sisters in New Haven, Connecticut, where he lived at the time, paired him with an 8-year-old boy whose father had died of AIDS and whose mother was soon to perish from the disease.

“It really completely changed my perspective on this idea that I call the random lottery of birth, where I’m born into a situation where I have two master’s degrees, no student loan debt, I have a future, and this little boy was an AIDS orphan before his ninth birthday,” Fetterman said. “The gap is too much; there’s just too much disparity.”

Fetterman quit his high-paying job and joined AmeriCorps, which sent him to Pittsburgh. A successful stint there helping adults upgrade their job skills led him back to school at Harvard’s Kennedy School of Government, where he grabbed a master’s degree in public policy.

He eventually settled in Braddock, a town of not much more than 2,000 people, mostly African-American, just outside of Pittsburgh. Once the community where Andrew Carnegie started his steel empire, the town was plagued by drugs, depression and, despite its small size, murder rates in the double digits.

Andrew Rush/ASSOCIATED PRESS Braddock Mayor John Fetterman walks through the former United Brethren in Christ Church in Braddock, Pennsylvania, on March 10, 2007.

Fetterman moved into the basement of an abandoned church and spent several years working, among other things, to get young men off the street corners, out of gangs and into GED programs. He ran for mayor in 2005 and won by one vote.

Since then, he’s put his heart into the place, tattooing its zip code onto one arm and the dates of the five murders in the town since his election on the other. He’s cleaned up vacant homes, started community gardens, attracted new businesses and development and built a community health center when the local hospital closed. His wife, a former undocumented immigrant from Brazil, runs a free store that gives out donated clothes, food and other goods.

In short, he’s the kind of leader who practices what Sanders preaches -- and he wants to take it to a bigger stage.

“I was born into a fortunate situation, and far too many millions of people in this country are born into a tough situation,” Fetterman said. “We can’t all be equal, of course, but I don’t think the gap should be as big as it is.”

In the context of 2016, Fetterman’s policy aspirations are not that different from those of many left-leaning Democrats. He backs a $15 minimum wage, a woman’s right to choose, immigration reform and tighter gun laws, although he’s a gun owner.

It’s the way he approaches those issues that puts him at odds with party leaders in Washington who have cast themselves as reasonable compromisers against Republicans who are unyielding obstructionists.

Fetterman believes standing in the way can have its place.

“I’m the only candidate in this race that’s proud to say I have litmus tests for any Supreme Court nominee that I would vote for, and first and foremost of those is repealing Citizens United,” he said, referring to the 2010 court decision that paved the way for unlimited corporate spending in campaigns.

This idea that you can compromise with crazy or unreasonable -- that’s not compromise, that is appeasement. John Fetterm

He also doesn’t believe in compromise for compromise’s sake when he views the other side as entirely unreasonable.

“This idea that you can compromise with crazy or unreasonable -- that’s not compromise, that is appeasement, and that doesn’t help anybody move it a long,” Fetterman said.

“When the other side is espousing these views that have no room for compromise, and they’re absurdist — we don’t argue about the science of the camera that’s recording me, we don’t argue about the science of our iPhones, but why are we arguing about the science of climate?” he said. “It’s just because someone’s gut says if it snowed last week, I don’t have to worry about it — you can’t really compromise on that.”

He allows that the divide in the country is especially broad right now, as seen in the rise of both Trump and Sanders. He sees both candidates as opposite sides of the populist coin, with Trump tapping into the destructive, dark side of populism embraced by so many in the tea party.

“This tea party, angry mindset -- they’ve just become performance artists. How many more dozens of times are they going to repeal Obamacare? How many dozens of more times are they going to scream and yell about transgender [people] using bathrooms, or that the world will spin off its axis if we grant marriage equality? The only marriage that I saw fall apart after [the Supreme Court upheld marriage equality] was Josh Duggar's,” he said.

He also takes the unpolitician-like position of not claiming to have all the answers, including how to bridge the gaping divide. But he promises to try.

“[I'm] not guaranteeing an outcome other than to say I guarantee to work hard to achieve that outcome,” Fetterman said.

He especially can’t guarantee the outcome of this election.

One of the biggest hurdles he points to is the spending in the race, which makes his chances of taking the step up especially slim. Party insiders are determined to advance McGinty, and the combined spending on her behalf by the DSCC and other outside groups exceeds $4 million. That’s on top of almost $3 million spent by her own campaign. Sestak’s campaign and a super PAC backing him have spent about $3.5 million.

Fetterman has only raised about $600,000, and state news coverage of the contest has been dominated by the battle between the better-known Sestak and the party’s choice, McGinty.

“The money in my race has had massive, massive influence,” Fetterman said. “It’s not about ideas, it’s not about experience, it’s not about debates, it’s about how much money can you bring in from outside forces and just carpet bomb the airwaves with television ads.”

In a large state like Pennsylvania, the barrage has left very little room for Fetterman, whose polling numbers have ranged from the single digits to the mid-teens.

At the same time, neither Sestak, who generally leads, nor McGinty are getting support above the mid-30 percent range in spite of all their spending.

Fetterman still sees a chance to make up the difference by Tuesday’s election, in which he may be able to count on many Sanders supporters swinging his way while Clinton backers split between McGinty and Sestak.

“We’re the green on the roulette wheel,” Fetterman said, admitting his path to victory is narrow. “A third of the voters are undecided, a third of each of their respective supporters aren’t sure who they’re voting for, and we believe that we are going to outperform those polls.”

And if he doesn't win, it's not like he plans to give up trying to realize his vision of a fairer, more equitable America.

"That path to running for the Senate has never gone through a community as poor and as on the fringe as Braddock," he said. "So it’s not like this was a plan that was hatched 15 years ago where I’m like, 'Hmmm, I’m going to win the first election in one of the poorest towns in Pennsylvania in Braddock by one vote and then in 2015-16, these issues that I care about now are going to suddenly be more in the forefront."

He added, "These issues that I’ve built my career around working against and championing, yeah, that’s certainly not going to change."