When Sen. Amy Klobuchar (D-Minn.) took herself out of contention to be Joe Biden's running mate last week, she made her reasoning perfectly clear. "I think this is a moment to put a woman of color on that ticket," she said."If you want to heal this nation right now — my party, yes, but our nation — this is sure a hell of a way to do it."

The context was obvious. America's cities have been convulsed for the past month by protests over police brutality and misconduct, and over the larger charge of systemic racism in American institutions. To pick a white Minnesota prosecutor with a long history of declining to indict police officers in shooting cases would be pouring salt on the wound and gasoline on the fire. By contrast, choosing a woman of color — especially a Black woman — could be a balm, and a sign that a Biden administration would take the concerns being voiced in the streets seriously enough to redirect that energy into electoral politics.

So what does it mean that so many of the high-profile Black women under consideration for the position are also ... cops?

The term was applied during the campaign to California Sen. Kamala Harris (now seen by many as Biden's most likely pick) — and it was not meant as a compliment. Before reaching the Senate, Harris spent most of her career as a prosecutor, first as San Francisco district attorney and then as attorney general of California. Though her tenure did feature initiatives that might appeal to a reform-minded moderate — her involvement in the anti-recidivism pilot program, "Back on Track," for example, or her implementation of anti-bias training for police — she has been harshly criticized, both by left-wing progressives and libertarians, for favoring tough punishments for drug crimes, sex crimes, and other offenses. She was seen as someone who overall abetted the expansion of the carceral state rather than someone who tried to rein it in.

Biden has another option in Florida Rep. Val Demings, a rising star from a key swing state — but the label applies even more plainly to her. Though Demings achieved national recognition as a co-manager of the impeachment trial of President Trump, she spent most of her career as an officer in the Orlando Police Department, climbing to become the first female head of the department in 2007. One can point to actions she took that could appeal to moderate reformers — including investing in quality-of-life improvements as a crime reduction strategy and advocating for a national registry of police shootings — and she has spoken out clearly about police misconduct as not only an affront to justice but a betrayal of the idealism with which she joined the force. But even before she ran for Congress, her record as police chief was being reassessed, from triumphant — a 43 percent drop in violent crime in four years — to a far more qualified success marred by continued complaints of excessive force.

A third option, Atlanta Mayor Keisha Lance Bottoms, cannot be described as a cop in any literal sense. But as a big city mayor, she has the direct responsibility for overseeing the police, and for making sure they preserve both order and justice in the city. That dual requirement has come under considerable stress in recent days. Bottoms has risen to prominence as a potential VP pick substantially due to an impassioned speech in which she denounced those engaged in violence and vandalism as "disgracing the life of George Floyd." But Bottoms has also participated actively in several peaceful protests, and, in the wake of the killing of Rayshard Brooks, announced a series of changes to use-of-force rules that have enough teeth in them to have prompted "sick-outs" by some officers in protest.

That last fact points to a particularly vexing aspect of this moment, one that must play a central role in any effort to convert anger into action, and that therefore should be highly relevant to assessing the possible import of Biden's choice. The sometimes brutal reaction to the Black Lives Matter protests revealed vividly what many Black Americans have been long familiar with: the police's too-frequent resort to force not only to counter a threat but to establish their authority. That should never be the way the police treat the citizenry in a democratic society. So the first order of business — regardless of what other reforms are contemplated — must be re-establishing civilian authority over the police.

But any such effort is extremely likely to face pushback by the police themselves. There's evidence that investigations triggered by "viral" incidents of deadly force lead to a marked increase in crime, as police take a step back out of concern for self-protection, hostility to the investigation, or a simple drop in morale. And as crime rises, it can fuel a political reaction that plays into the hands of the most recalcitrant opponents of reform. We're living through the largest such viral moment in memory, with national and even International implications. It's difficult to overstate the challenge this poses for reformers, to say nothing of police-abolitionists who want to radically rethink how order can be maintained in a free society.

Policing is mostly a state and local matter. But it seems highly likely that a Biden presidency, if backed by a Democratic House and Senate, would take some actions to push America's police departments in the direction of reform. The question is whether that push is advanced grudgingly or with determination, and whether it is received soberly or with scorn.

Which brings me back to Biden's choice. If he chooses a Black woman simply out of the desire to reward a crucial constituency, that would be entirely in keeping with the tradition that gave America Vice Presidents like Johnson, Mondale, and Pence. And anyone Biden chose would bring significant talents to the table.

But the three choices noted above would signal something more specific. They each have direct experience with the relationship between the police and the citizenry. They know that relationship from the inside, albeit from importantly different angles. They would be better positioned than Biden himself to push back against the most radical demands that have emerged — but they would also have more credibility to legitimate some of those demands, and push them through over the objections of obstreperous police departments and citizens anxious about a rise in crime. It all depends on what they — and their prospective boss — truly believe is necessary now, and how much they are willing to put on the line to achieve it.

The history of running-mate selection suggests that Biden himself doesn't yet know who he is going to pick. He has already said that his priorities are picking someone capable of being president and with whom he feels confident he could have a strong working relationship. That emphasis on governance is welcome. But a big part of governance is keeping your coalition with you as you tackle difficult problems in office. The right running mate could help thread the needle, bringing America's police departments around to seeing that they must change to truly serve, while also convincing an outraged citizenry that the change on offer might actually be worth investing with hope.