Nearly 12 years ago, Barack Obama began staffing his administration in the middle of a global economic crisis. Despite the high hopes of the progressive forces that catapulted Obama into office, his transition set the tone for a presidency that would be steered by corporate insiders.

In one notorious example, Citigroup continued to pay a top executive, Michael Froman, while he served on the board of Obama's transition team, playing a key role in filling the administration with Wall Street insiders, whose firms were seeking government support amid the financial crash.

Citibank would receive more bailout money than any other bank, and Froman would go on to serve a variety of roles in the administration.

If former Vice President Joe Biden wins in November, his administration will be tasked with rebuilding a devastated economy while recovering from a deadly public-health crisis. Faced with comparable challenges, Obama gave the reins to former investment bankers, hedge fund managers, corporate lawyers, and others who had profited handsomely from the industries they were supposed to regulate.

That can't happen again.

Sen. Bernie Sanders of Vermont, who endorsed Biden on Monday, will now begin urging his movement to support Biden in a general election against President Donald Trump. The Sanders campaign has been focused on numerous marquee policy proposals: "Medicare for All," the Green New Deal, free public college, a jobs guarantee, and an end to endless war.

In a livestream Monday, Biden and Sanders announced joint policy task forces dedicated to finding common ground on the economy, education, criminal justice, immigration, climate change, and healthcare.

But what Sanders' movement must demand from Biden is not mere words of support for aspects of this agenda. Rather, Sanders must secure commitments that people willing and able to implement the Sanders agenda are installed in high posts in a Biden administration.

A policy-based promise alone is essentially unenforceable. The process of passing legislation or even implementing a rule is lengthy and tortuous, presenting myriad opportunities for unjustifiable compromise, concern-trolling about how a proposal will be received by the courts or Congress, unwillingness to expend sufficient political capital, and untold other sorts of interference by individual staffers and appointees.

The public won't even necessarily know if efforts to secure a policy victory were undertaken earnestly, and we will have little recourse if it is not.

To achieve confidence that such setbacks would be navigated in good faith, Sanders supporters must demand a Democratic administration staffed by people the left can trust, who will dedicate themselves to enacting and enforcing a progressive agenda and who will blow the whistle if their efforts are stymied from within a Biden White House.

Conversely, progressives must also draw red lines excluding people who would work to undermine any such advances.

Don't make the same mistake

Twice in the past month, lists of ostensible Biden appointments have been leaked to the press. Both instances leave the impression that Biden is willing to leave crucial executive decision-making to bankers and billionaires.

An Axios article from March 9 floated the Bank of America executive Anne Finucane and JPMorgan Chase CEO Jamie Dimon for Treasury, as well as the Morgan Stanley executive Tom Nides, the Harvey Weinstein confidante Anita Dunn, and the billionaire Mike Bloomberg for other key posts.

Last week, Biden reportedly told a group of donors he was considering billionaire BlackRock CEO Laurence Fink; Blackstone's executive vice chairman, Tony James; and the investor bankers Mark Gallogly and Roger Altman.

In both pieces, Sen. Elizabeth Warren's name came up as a bone to be thrown to the left. And indeed, Warren would be a welcome inclusion in a Biden White House, but her ability to protect the interests of working people would be stymied if the rest of her colleagues are looking out for bankers, wealthy shareholders, and their own stock portfolios.

As we have argued here previously, the task for both Sanders and Biden is to unite the party and defeat Trump. But Sanders' recent exit far from guarantees that outcome. Biden will succeed in bringing along the Sanders coalition only if he can prove to them that their reasonable, progressive demands will be prioritized.

Several days before the last debate, after a disappointing Super Tuesday, Bernie gave a speech in which he laid out a series of pointed policy questions he wanted Biden to address. He must also demand that Biden answer another set of concerns — to which "no" is the only acceptable answer:

Will he actually consider appointing Dimon, Fink, Dunn, Bloomberg, and their ilk to high office within his administration?

Will he consider appointing titans of the health insurance and pharmaceutical industries in key posts that oversee public health?

Will he appoint corporate lawyers to run the Department of Justice or key posts within it, like head of the antitrust division?

Will his administration welcome people who have spent their careers profiting from work that is at tension with progressive values and the public interest?

If Biden is unwilling to answer the above questions unequivocally, his stated goal of "earning" the votes of Sanders supporters may be impossible.

Uniting the Democratic Party

On Wednesday, a group of youth-led progressive organizations, many of which endorsed Sanders in the primary, issued an open letter to Biden listing commitments he should make to earn the trust of young, progressive voters. Among them was an extensive list of personnel demands, including a pledge to "appoint zero current or former Wall Street executives or corporate lobbyists, or people affiliated with the fossil fuel, health insurance or private prison corporations, to your transition team, advisor roles, or cabinet."

This is a welcome sign. To our peril, the left has tended to neglect personnel decisions in making demands of Democratic administrations, focusing their energies instead on extracting policy concessions.

The Obama administration is case in point. A genuine populist tide swept Obama into the White House, where he proceeded to sideline the unions and grassroots organizations that enabled his victory while fortifying the power of the banking industry amid a national catastrophe created by their greed and indifference.

At the moment, progressives have reason to suspect Biden will make the same mistakes. It is Sanders and his supporters' responsibility to demand that he does not, and Biden's responsibility to agree — in the interest of the progressive values he claims, bridging divides within the party and boosting the energy needed to ensure Trump's defeat.

Only a united Democratic coalition will ensure a victory over Trump in November, and only a Democratic administration committed to aggressive policymaking in the public interest can steer the country out of the twin economic and health catastrophes we are living through.

Both require attention to the actual people, their career commitments and values, who will compose the next Democratic White House.

Sam Adler-Bell is a freelance writer in New York who has written for The New Republic, The Intercept, and other publications. He cohosts the podcast "Know Your Enemy."

David Segal is a former Democratic Rhode Island state representative and served on the Providence City Council as a member of the Green Party. Segal's opinion pieces have appeared in The New York Times, The Boston Globe, and other newspapers.

Published by Business Insider.