I was standing at a strip mall in Iowa, the state where presidential campaigns are born and often die, and Cory Booker was about to walk in the door.

Gretchen Aschoff, 55, a nurse in Cedar Rapids, was waiting for him.

“I am enraged, and I am looking for someone to channel my rage,” said Aschoff, not really sure if the junior U.S. senator from New Jersey could be the one.

For Booker — and all the other candidates aiming to take on on President Donald Trump in 2020 — that may be the key issue. Many disaffected Democrats say they are looking for a firebrand to unleash the fury kindled by a Republican president they see as unqualified, undisciplined and sometimes unhinged.

They want a living rage doll to scream for them.

It is not a role Booker has cast for himself. Even at this strip mall, he talks about "the lines that divide us are nowhere near those that unite us.” And now that he has entered the presidential race, he faces a high-stakes dilemma — will a party rocked by outraged Berniecrats shrieking, “I told you so!” for the last three years pipe down long enough to hear him out?

Or more pointedly, is Cory Booker “progressive” enough to unite the Bernie Bros, Blue Dogs, Green New Dealers and who/whatever the hell else is carving up the Democratic Party ahead of 2020? Will all these disparate progressives be in any mood to trade purity for unity when they believe that’s what cost them the election last time?

When I sit down with Booker in New Jersey to ask him this a few weeks after his Iowa trip, he acknowledged the problem, but said it’s one of semantics, not politics.

“My problem is that these labels mean different things to different people,” Booker observed, sliding into a Montclair diner booth to have a conversation about how he might surf the blue wave that flipped the House of Representatives all the way to 1600 Pennsylvania Ave.

“I label myself a progressive, but that’s not how I start,” said Booker as he stirred some almond milk into his coffee. “I start with where my values are. My passion has always been Issues of poverty, issues of housing, issues of injustice."

To be sure, Booker has proposed — and succeeded — in passing some recent bipartisan initiatives that have met with applause from the left, like sentencing reform.

But many of the progressive ideas he supports may stand little chance. Booker supports a guaranteed universal income, and an innovative “baby bonds” program that would set up all Americans with a $1,000 trust account at birth that they could use to buy a home or pay for college. Appalled by the Flint, Mich. water crisis, he’s sponsored bills strengthening environmental protections for America’s poorest.

Yet progressive initiatives that have had actual, broad-based Democratic support — like importing generic drugs from Canada to alleviate price-gauging of seniors — are where Booker’s faltered in the past. Some progressives wonder if, when this guy addresses powerful, moneyed Wall Street interests, will he speak truth, or ask for a donation?

“If you go outside New Jersey, people think he’s wonderful,” said Berton Lefkovic, a New Jersey progressive activist and Bernie Sanders delegate in 2016, “But inside New Jersey, progressives don’t trust him. He’s given progressives in New Jersey more than enough reason not to trust him."

Lefkovic points to a now-infamous January 2017 amendment to “lower prescription drug prices for Americans by importing drugs from Canada" that failed in the Senate, noting that Booker was among the 52 senators who narrowly killed it.

Until recently, Booker has tried to explain it away as only a symbolic amendment — a non-binding measure that doesn’t get signed by the president or become law — and that he voted ‘no’ only because of genuine concerns about the safety of such drugs.

Then, recently, Booker stood next to Democratic socialist U.S. Sen. Bernie Sanders, I-Vt., at a press conference and decried the “outrageous and unjustifiably high cost of prescription drugs.”

U.S. Sen. Cory Booker stands between U.S. Sen. Bernie Sanders, I-Vt., and Rep. Ilhan Omar, D-Minn., at a Jan. 10, 2019, press conference at the Capitol announcing legislation to lower the cost of prescription drugs.

Booker then signed onto drug pricing reforms that would allow Medicare to negotiate drug prices, strip drug companies of a monopoly if their prices rose above those in other developed nations and, yes, to allow the importation of drugs from Canada.

“I’ve always supported imports," Booker said, rewriting history just a teensy bit. “And we have a piece of legislation right now that will ensure safety, will drive down costs to taxpayers and will give people access to prescription drugs.”

But his lack of full-throated support when the electoral stakes were at their lowest gives progressives like Lefkovic pause.

“Obama was for a public option — until he wasn’t. Booker also says he’s for a single payer, (healthcare system)" Lefkovic said. “I’ll believe him when he casts a vote for it.”

FLIRTING WITH THE WRONG CROWD?

When first running for the U.S. Senate in a 2013 special election, Booker took almost three-quarters of a million dollars from the securities and investment industry. By 2014, when he sought reelection — in an uncontested primary, by the way — Booker received $1.87 million from Wall Street. That was more than the top Republican recipient, Senate Majority Leader Mitch McConnell of Kentucky pulled in that very same year.

Even Booker seemed to acknowledge the problem last February: After progressive candidate Alexandria Ocasio-Cortez promised not to accept donations from political action committees, she crushed longtime U.S. Rep. Joe Crowley, D-N.Y., making him the first House Democrat in the nation to lose a primary in 2018.

Almost immediately, Booker took the same no PAC money pledge as Ocasio-Cortez, saying that the campaign finance system was “broken."

It may or may not help that a giant Wall Street reformer is sticking up for Booker on this front. Former U.S. Sen. Christopher Dodd, D-Conn., whose name is synonymous with the most comprehensive curb on the power of Wall Street’s banks of the last decade, the Dodd-Frank Act. Dodd predicts it won’t be crippling, especially given his track record on other progressive issues.

“There will be some who try to bring up anything to disqualify someone, but I will quickly add that in Cory’s case, it shouldn’t,” said Dodd in an interview with NJ Advance Media.

“I know Cory pretty well," said Dodd, who himself ran for president but lost to Barack Obama in the 2008 Democratic primary. " I don’t necessarily draw the conclusion that because someone has received contributions that they all of a sudden have been ‘bought’ by the (banking and financial services) industry."

At the same time, unlike Bernie Sanders and Elizabeth Warren, who have raised more than half of their campaign cash from grassroots giving, Booker has the lowest percentage of small-donor funds of any senator weighing a presidential bid. He relies on Wall Street cash more than any senator from either party. And he also came within a cat’s breath of being Hillary Clinton’s running mate, with the campaign reportedly going so far as to have Clinton-Booker 2016 signs printed up.

But forget the money for a second. Can Booker even wear the progressive mantle? Does a guy who burnished as a reformer in the hardball political arena of New Jersey, often doing so with a message of conciliation and a frequent stump speech that used the word “love,” have the street cred to carry a progressive message?

“Candidates have been calling themselves ‘progressive' all over the political spectrum because they realize that’s where the energy and momentum is in the Democratic Party,” said Neil Sroka, communications director for the left-leaning advocacy Democracy for America, which grew out of Gov. Howard Dean of Vermont’s 2004 bid for the White House.

“But 'progressive’ in politics has become like ‘whole grain’ in cereals ," Sroka said. "So Democrats are like, ‘Yeah, I want that, but I need more before I trust you just because you call yourself that.’ ”

Steve Phillips, a San Francisco-based civil rights attorney and Democratic donor, has created a super PAC called Dream United that’s already raised $4 million to run issue ads, even though it can’t contribute to or coordinate directly with a Booker campaign.

”There’s nobody more eloquent or passionate addressing poverty and promoting racial healing than Cory Booker. And there’s clearly a desire for younger leadership. But how do ‘progressives’ relate to the country’s profound and persistent racial inequality, as well as economic inequality? We’ll have to see.”

Even Booker acknowledges the progressive label can mean different things to different people.

“There are people who label themselves progressives, who think I am a progressive champion star, and have a whole bunch of evidence for that," he said."And then there are people that progressives who prolly think that I am not Bernie Sanders and therefore not pure in some way, and that’s OK."

On the national stage, Booker has repeatedly told the story of how he and his parents were very nearly shut out of decent housing over racial bias and how that motivated him to enter public service.

“I’m a guy who grew up in Bergen County in an affluent town that we almost didn’t get into because of the messed up housing policies in the state of New Jersey,” said Booker at our sit down in Montclair, patting the diner booth’s table for emphasis. “We have a shameful history of housing policies that disadvantaged people based on race and income. And I was very aware of that as a young black kid growing up in a white community, so by the time I was a teenager, my mission was to deal with these inequities."

Yet Booker has a way of effectively playing to both sides.

During a trip to Iowa in October to campaign for the midterm elections, I watched as Booker went out of his way to simultaneously take a shot at Wall Street and plant a kiss on public school teachers.

“Who contributes more to this economy?” Booker asked of a crowd of family farmers in Boone, Iowa in October. “A 25-year-old stock broker in New York who makes a million dollars a year, or a 55-year-old school teacher who educates the workers of the future?”

As the crowd exploded into sustained applause, Booker thundered on. “Who should get the tax breaks? Who should get the loan forgiveness? Who should get free college?” Cheers erupted.

“There’s still a lot of distrust over all the corporate money and the charter schools, so that’s going to be a big question mark hanging over him,” said Jordan Zakarin, founder of Progressives Everywhere, a newsletter and website that spotlights and fundraises for progressive Democrats around the country.

CARRYING THE PROGRESSIVE TORCH

It’s true Bernie Sanders was the top 2020 choice of self-identified progressives surveyed by the progressive political action committee Democracy for America in December, drawing 36 percent of the 94,000 progressives surveyed. And Booker, it should be said, was at the bottom, in single digits. But so were liberal darlings like U.S. Sens. Elizabeth Warren of Massachusetts and Kamala Harris of California, as well potent swing state Democrats like Sens. Sherrod Brown of Ohio and Amy Klobuchar of Minnesota.

In short, no single potential presidential candidate has full command of the Democratic Party’s progressive base.

Cory Booker will face at least three other Democratic senators in the race for president in 2020, including Kamala Harris, D-Calif., (right), as well as Elizabeth Warren of Massachusetts and Kirsten Gillibrand D-N.Y. (PennLive file)

“A big chunk of Bernie’s support was that he was not Hillary,” Phillips said. “That constituency has many more options now., and a lot of young people seeking new energy and authenticity see that in Cory."

Perhaps having watched former Gov. Chris Christie’s disastrous effort to rebrand himself as an arch-conservative in 2015, Booker doesn’t seem to be terribly interested in shoe-horning himself into progressivism’s glass slipper.

“Those people didn’t care about the labels; they only care that they came home and had a job,” Booker said. “I know if i run in a national election, I’m not going to win 100 percent of the vote. There are people who are going to be staunchly against me, and I can do nothing about it."

Indeed, many angry — livid, really — progressive voters I spoke with as I followed Booker through Iowa say his message of “radical love” for countrymen who’ve supported Trump policies they view as racist and boundlessly cruel say he’s asking too much of them.

Dodd, having been steamrollered by Barack Obama’s theme of “Hope” in the Iowa Caucuses of 2008, thinks that Booker’s use of an uplifting message will ultimately resonate.

“It’s an aspirational country,” Dodd said. "We’re a big bunch of dreamers. You can mess with all of reality, that doesn’t bother me. You mess with my dreams, I’m going to have problems with you. Obviously, Cory understands that.”

Perhaps where Booker is most clearly out of step with progressives is his lack of rage and bile. Progressives now outnumber conservative Dems 4 to 1 in Congress, and the liberal-leaning bloc is now the largest, most powerful and arguably the angriest it’s ever been. Booker, by comparison, speaks of the word “patriot” as meaning someone who loves their country, and he argues you cannot love your country without loving your fellow countrymen and countrywomen.

That “radical unity of Obama” isn’t what progressives want right now, Zakarin said.

“It’s not that progressives are looking for anger," Zakarin said. “Progressives don’t want a candidate who says ‘Let’s get back to more civility.’ They want someone who will acknowledge things are screwed up, that we need, big, big changes. When AOC talks about the ‘Green New Deal,' it’s not the just the green part that resonates; it’s the New Deal part.”

When I asked Booker if he’s not letting down angry voters who want a candidate to carry their message with fury, he offered a disarming response.

“Nobody can say that my hero, Dr. King, was not a hard fighter, that he didn’t stand up and fight Bull Connor,” Booker said, referencing the Commissioner of Public Safety for the city of Birmingham, who infamously turned attack dogs and water cannons on civil rights marchers.

“He just used a really ingenious strategy that took Bull Connor’s energy as, like, a jiujitsu move, and used judo to use his energy against him.”

And it’s probably true that you can’t prevail in a depravity contest with Bull Connor.

“I don’t think you win — and I’ve watched Marco Rubio and a whole bunch of other people try it, including Elizabeth Warren recently trying to take him on his Native American slurs — I don’t think you win with Trump by fighting him on his turf," said Booker, draining his coffee mug.

He stared at it a moment.

"So for me, this is about staying authentic: No matter what I choose to do, (seek) reelection or President of the United States, I want to stay in my authentic space that I’ve been in for 20 years in American politics. And you know what? I’m a black guy and a United States senator. It’s kinda worked,” said Booker, before pausing to add. “You know ... so far.”

As for Gretchen Aschoff back in Iowa, she remains concerned that Booker couldn't, or wouldn't, be able to give voice to the very real anger that Democrats were feeling without alienating voters. She was not taken in by his stump speech talking of what unifies us all.

"This is not a ‘Kum-ba-ya’ moment,” she said. “So I think he’ll make a very good...Senator.”

When I asked Booker about what she said, he remained unfazed.

“You’re gonna walk into any room, two people are going to like you no matter what you say. Two people are going to hate you, no matter what you say. You can’t do anything to change that,” Booker said. “But there’s six people in that room you’re gonna talk to. I’m trying to talk to people who are open to listening, open to hearing my ideas, open to feeling my spirit.”

Claude Brodesser-Akner may be reached at cbrodesser@njadvancemedia.com. Follow him on Twitter @ClaudeBrodesser. Find NJ.com Politics on Facebook.