(CNN) In Washington, the political world was on edge as it waited for the long-anticipated release of special counsel Robert Mueller's report on the Russia investigation.

In Boston, Elizabeth Warren's policy team was also waiting -- but for a different kind of document.

It came on a Monday in mid-April, as Warren was kicking off a three-state tour around her new offshore drilling and public lands proposal.

"I love data!" she wrote in a memo that was viewed by CNN. "Yes, I'm on board for $50K in forgiveness for everyone under $100k in family income, with smooth transition from $100K to $250K. Yay!"

It was a critical sign-off for Warren's landmark student debt forgiveness relief plan . She and her advisers would volley memos back and forth for several more days before the senator ultimately issued a final verdict on the plan. One aide would call it, "The Decision Memo."

Warren's personal involvement in her sweeping student loan relief plan -- and her decision to make it a cornerstone of her presidential candidacy -- provides a crucial snapshot of the internal workings of a campaign that has widely become regarded as one of the most policy-driven in recent history. Behind Warren's rise in recent polls is a campaign machine churning out a stream of policy proposals -- all overseen, and constantly tinkered with, by Warren herself.

Over the course of several weeks, CNN interviewed Warren's most senior campaign aides and visited the senator's headquarters in Boston to assemble the clearest picture yet of how Warren's policy plans come to life.

Warren, her advisers say, has been an intimate part of crafting every one of the 23 policy plans her campaign has released so far this year. In many cases, the priorities come from her directly, like her proposals for student-loan forgiveness and free public college. In others, Warren has picked up on ideas from experts or even regular voters - her idea to nominate a public school teacher for education secretary, for instance, came from a teacher who spoke to her in a photo line.

"Every one of the decisions is her decision," Jon Donenberg, Warren's policy director said in an interview. "Both from the beginning of what do we want to focus on and when and how, all the way up to what level of detail do we have in the proposal."

"Emails at all hours of the day"

Warren's campaign headquarters in the Charlestown neighborhood - a 10,000 square foot ground-floor open office space in a nondescript brick building -- would mostly be lacking in color were it not for the campaign posters, handmade signs and Post-It notes plastered across the gray walls.

Hanging over the four-people policy team is a handwritten sign that reads, "Dream big, fight hard, write plans." On another side of the office are giant cut out letters that play off of Warren's popular "I've got a plan for that" slogan: "She's got an algorithm for that." And more than a dozen Medium entries cover another wall - essays on Warren's major proposals including on housing, the opioid crisis and corporate taxes.

"On some level, everyone who's working on this campaign is working on policy, more than they ever have," said Roger Lau, Warren's campaign manager.

Warren's closest advisers here describe their boss as a voracious academic who is constantly reading in her spare time, including on her laptop when she is out on the campaign trail. The former bankruptcy law professor has a seemingly unlimited appetite for case studies, research papers and news articles, some of which are flagged by friends and former colleagues from her pre-Washington years.

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Warren passes along her thoughts and questions to aides in "emails at all hours of the day," said Donenberg, who described the senator as being singularly focused on one theme.

"She spent 30 years in her career studying really one central question, right? Which is: what is going wrong with America's middle-class families?" said Donenberg, who has been working for Warren since her first Senate race in 2012. "Why are people working harder than they've ever worked before and not seeing raises and seeing their expenses go up? Why is their debt increasing? Why do they feel like opportunity for their kids is slipping away?"

A challenge since Warren's exploratory campaign launched on New Year's Eve, he added, has been prioritizing their long to-do list: "There's only so many hours in the day."

But there was never any question that two issues would be central to Warren's presidential platform, and that they would come early in her campaign: universal childcare and student loan debt relief. Warren describes both as deeply personal concerns, stemming from her experience attending public college and raising children as a working mom.

"This is what I heard; this is what someone told me"

Other ideas for Warren's policy plans are coming directly from voters.

After each of her events, Warren takes photos with anybody who waits in line - a process that can take several hours. The campaign boasts that she has now taken more than 30,000 photos with voters. And when she is done snapping pictures, Warren writes an email to a handful of aides.

The note, usually in bullet-point form, can be so detailed that the senator has even described what a particular person was wearing when they raised a question or concern.

"She writes all of this stuff down," Lau, who has been working for Warren since 2011, told CNN. "This is what I heard; this is what someone told me; this is an interesting tidbit. Some of them are cute stories, some of them are policy ideas."

After a campaign event in Long Island City, New York, in March, a teacher floated the idea of appointing a public-school teacher as education secretary. The suggestion stuck, and weeks later, Warren announced her commitment to doing this if she were elected president.

The " student loan calculator ," a tool on Warren's campaign website, was also born out of the photo line.

"Something she kept hearing was: 'How much student loan debt would be canceled for me under your plan?'" said Warren's communications director Kristen Orthman. "She said, 'Is there an easy way to make it so that people know how much debt cancellation they can get?'"

Orthman said the calculator was so popular that the campaign replicated it to create the "universal childcare calculator," a way to determine how much money a family could save under Warren's plan.

"Inclusion beyond just class, but also about race"

There is no typical day for the Warren policy team.

They have drafted hundreds of memos for Warren this year, and they shuffle between conference calls and meetings, and rarely have the luxury of focusing on just one proposal. Much of their time is also devoted to surveying academics and policy experts, whose opinions and research Warren relies on heavily.

Darrick Hamilton, a stratification economist who studies racial and ethnic inequality, told CNN in a recent interview that he had multiple phone calls with Warren's top policy aide Bharat Ramamurti about student loan debt forgiveness and housing.

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Warren's policy team was looking to his expertise to ensure their proposals would have "inclusion beyond just class, but also about race," Hamilton said. In their conversations about student loan forgiveness, Ramamurti zeroed in on the "racially regressive impact" that could have on blacks, Hamilton said.

According to advisers, it's this kind of data and analysis on potential economic impact that is presented to Warren before she gives final sign off. The senator also requests specific examples that she can point to on the trail: when she recently unveiled her "economic patriotism" plan, she called out Levi's and other American companies that had shipped jobs overseas.

When a policy release coincided with the Mueller report

The planning for a policy rollout often entails selecting a location that thematically fits with the issue.

Warren introduced her break-up-big-tech plan in Long Island City, where Amazon had unsuccessfully attempted to open up a second headquarters; the senator traveled to Kermit, West Virginia, a town devastated by the opioid epidemic, to discuss her vision for tackling the addiction crisis; and the "economic patriotism" phase of Warren's campaign was coupled with a trip through the industrial Midwest.

Orthman, Warren's communications director who oversees the rollout strategies, recalled one time when things did not go according to plan. The campaign was eyeing a Thursday in April to release its student loan debt relief plan, ahead of a CNN town hall on a college campus. But then came word that the Mueller report would be coming out on the same day.

"Obviously we're not going to release our plan the day of the Mueller report," Orthman said. (The campaign ultimately pushed the plan's release until the following Monday).

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On a recent Thursday afternoon, 14 staffers gathered to talk through a plan unveiling coming the next day: a $7 billion "Small Business Equity Fund" aimed at boosting grants to entrepreneurs of color.

The meeting was a rapid-fire around the table. A policy aide explained why minorities are half as likely to start their own businesses as non-minorities and how the new proposal sought to remedy that. The political team described the outreach calls that would begin that afternoon. The social team confirmed that tweets and graphics were ready to be sent. The mobilization shop said text messages would alert supporters that the senator had a new plan. Warren's in-house video team said it would be on site to film Warren's remarks at the Black Economic Alliance forum in South Carolina.

Finally, the communications team laid out how the proposal would be distributed to reporters under a morning embargo, and that an exclusive op-ed had been placed in Black Enterprise magazine.

After the meeting, Orthman remarked upon what a difference several months had made for the campaign - that there was nowhere close to this kind of infrastructure in place when Warren released her first major policy proposal, the "wealth tax," in January.

"The fact that we did that first and then from there came a lot of these other plans, some that were paid for by the wealth tax?" Orthman said. "I didn't know at the time, but I look back at that, and see how important that was."