On Friday morning, Elizabeth Warren, who has officially been running for President for a month now, announced a proposal to break up the big tech companies—Amazon, Facebook, Google. On Friday night, she held a rally in Long Island City, the Queens, New York, neighborhood that Amazon recently chose for one of its new corporate headquarters, before changing its mind when activists, progressives, and union leaders criticized both the company’s labor practices and the deal it got from New York lawmakers. “Hello, Long Island City,” Warren said as she took the stage. “I understand you had a visitor.”

The rally—a thousand people standing with their jackets on in an unheated industrial space—gave Warren a chance to explicate her plan. In her stump speech, Warren talks about how her first ambition in life was to be a schoolteacher. Her rallies aim to educate. Diagnoses and prescriptions, not narrative or communion, are what’s on offer. On Friday, she spoke for a few moments about the mechanics of online platforms, e-commerce, and market competition, before offering an analogy. A company that runs a platform and also sells goods on that platform, like Amazon, she said, wants to be “the umpire in a baseball game, and they also want to run a bunch of teams in the game. So my view on this is you can be an umpire, or you can own a team, but you can’t do both at the same time.” People cheered for the analogy.

Warren’s broadest argument—her overarching theory of what’s wrong with America, and how to fix it—concerns corruption. “Corruption, plain and simple,” she said Friday. “Understand, whatever issue brought you here tonight, whether it’s income inequality, whether it’s climate change, whether it’s gun safety, whether it’s student-loan debt burden, whether or not it’s affordable child care, whether or not it’s housing—whatever brought you here tonight, I guarantee there are decisions made in Washington that directly touch on every one of those issues, and those decisions run straight through the problem of corruption and money in Washington.” She ran through her arguments for combatting corruption, which include lobbying reform, a tax on extreme wealth, and overturning the Supreme Court’s Citizens United decision. Then she took questions. The third question, from a man named Alex, was about homelessness. “O.K., thank you, Alex,” Warren said. “Let’s start with our values here. And that is: in the richest country in the history of the world, people should not be sleeping on the streets because they don’t have money.” Warren paused for applause before adding, “And I’ve got a plan.”