"That is the arrogance of billionaires," said Sanders, referring to reports that if Bloomberg runs he doesn't intend to participate in early-state primaries.
"I'm doing five events this weekend right here in Iowa," Sanders continued. "We're all over New Hampshire, South Carolina, Nevada, California. But he's too important. You see, when you're worth $50 billion, I guess you don't have to have town meetings, you don't have to talk to ordinary people. What you do is you take out, I guess a couple of billion dollars, and you buy the state of California."
"I don't think billionaires should be president right now," Ocasio-Cortez added. "I don't think that that's what this country needs, and I think that is going to take us further in the direction of wealth and political power concentrating at the very, very top of our country, and I think that our democracy should be for everyday people, not for purchase."
Ocasio-Cortez also cited Bloomberg's support of the New York Police Department's use of stop-and-frisk measures, widely considered to be racially discriminatory, as a major issue he'd have to confront during a campaign.
"To this day, he still defends his policy of stop-and-frisk, which impacted families like mine," the congresswoman said. "It was my cousins and my friends that were stopped on the New York City subway system and racially profiled and patted down and thrown into jail for low-level marijuana offenses."
The pair took to the campaign trail in the Hawkeye State less than three weeks after Ocasio-Cortez publicly announced her endorsement of Sanders' bid at a massive New York City rally. Ocasio-Cortez attended three events with Sanders and addressed thousands of supporters. She also knocked on doors to rally support in Des Moines.
Ocasio-Cortez met with Sen. Elizabeth Warren before she ultimately decided to endorse Sanders. The New York congresswoman said Sanders' Medicare for all plan and decades-long progressive record are what swayed her.
"It's about a personal story and a personal history, and I think his history and commitment is unique," Ocasio-Cortez added. "I think we're so used to electoral cycles about being the lesser of two evils that we are not used to selecting the best of great options."
On impeachment, Sanders and Ocasio-Cortez agreed that former Vice President Joe Biden's son Hunter, whose former position on the board of a Ukrainian company was at the center of President Donald Trump's calls for that country to investigate the Bidens, should not be called as a witness in the impeachment probe.
The congresswoman criticized House Republicans, accusing them of turning the probe into a "partisan issue." She also said calls to out the whistleblower were "profoundly dangerous."
"We need to protect the rule of law in the United States of America," she said, adding that the in relation to the impeachment probe, Republicans are "trying to turn this into a sideshow, and it's undignified and it's wrong."
"What Republicans are trying to do with Hunter Biden," Sanders added, "is clearly to deflect attention from the impeachable offenses of Donald Trump."
The senator added that he will attempt to maintain his rigorous pace of campaigning should impeachment go to trial and his presence be required on Capitol Hill.
"I guess I'm just going to have to try to be in Washington, D.C, in Des Moines, Iowa, and Concord, New Hampshire at the same time," Sanders said. "I will do my best."
With an eye on 2020, Sanders pledged that his partnership with Ocasio-Cortez would continue should he win the presidency.
"If I am in the White House," Sanders added, "she will play a very, very important role, no question, in one way or the other."
Sanders was asked what type of role.
"No hints," he said.