Rep. John Lewis joins the Congressional Black Caucus Political Action Committee in endorsing Democratic presidential candidate Hillary Clinton. (J. Scott Applewhite/AP)

Last Thursday, the Congressional Black Caucus PAC announced its endorsement of Hillary Clinton for the Democratic nomination. It was a media event, and outlets faithfully reported Clinton’s endorsement pickup as a potential key to winning black votes in upcoming primaries — especially the fast-approaching South Carolina contest, where black voters are expected to be key. In the 2008 election, black voters constituted 55 percent of the Democratic vote in South Carolina.

So what, exactly, does an endorsement like this do?

Possibly more than you think.

When do black leaders’ endorsements influence black voters?

In the most straightforward sense, endorsements such as the one issued by the CBC PAC can be important signals to black voters about the likelihood that a candidate will represent their interests — much as party labels signal a range of likely policy commitments to partisan general election voters.

On this straightforward effect of black political endorsements of white candidates, political scientist Andrea Benjamin has an important new paper. Benjamin conducted an experiment that presented black respondents with consistent information about candidates in an electoral context absent contrasting partisan cues (as the Democratic primary is). But she randomly assigned some to receive the additional information that an association of black political leaders was endorsing one of the candidates. The result: an increased likelihood for blacks to vote for the endorsed (white) candidate.

Sometimes.

Benjamin’s study took seriously the notion that black Americans aren’t “blind followers” — a point that many prominent African American commentators have been trying to make this electoral season. So Benjamin manipulated not only the presence of the black endorsement but also the presence of information suggesting the endorsed candidate actually had taken some political action in favor of black interests. In Benjamin’s study, the candidate opposed a government contract that, it was suggested, had been awarded despite failing to adhere to affirmative action policies or to seriously consider a minority company’s bids.

The result: Black respondents were unmoved by a black endorsement when there was no other cue to the candidate’s commitments on matters of race. When the endorsement was tied to a white candidate’s record on racial issues, however, the black leaders’ endorsement increased their support.

The takeaway for the Democratic primary campaign trail, then, is that the content of the endorsements the candidates line up matters. The endorsements aren’t likely to be useful voter signals unless they contain the right policy signals. Benjamin’s results are consistent with the argument that black voters turn to black leaders not for their stamp of approval, but for their justified argument in favor of a candidate’s likely representation on matters of race.

The Congressional Black Caucus gave the right kind of nod

With the results of Benjamin’s study in mind, the CBC PAC endorsement announcement becomes all the more meaningful for Clinton. The CBC PAC’s official endorsement statement was filled with policy, giving Clinton nods for her record on issues from racial profiling to voting rights to minority business interests. Rep. Gregory W. Meeks (D-N.Y.) presented her as a long-trusted partner for CBC members’ goals. And, perhaps most important, Rep. John Lewis (D-Ga.) used the CBC PAC announcement as an opportunity to challenge the legitimacy of Sanders’s claim to a similarly long-standing record.

In other words, the CBC PAC gave Clinton exactly the right kind of nod. One that carefully connected her to a policy record, while raising doubts that Sanders’s endorsers could really do the same.

On the other hand, there’s no consensus among black leaders yet — and that matters, too

But maybe it’s more complicated than that.

While the CBC PAC endorsement is yet another on a growing list of black political leaders’ endorsements for Clinton, it certainly does not signal an all-encompassing consensus of black elites. Some CBC members, including Rep. Barbara Lee (D-Calif.), have made their still-neutral stances clear. CBC member Rep. Keith Ellison (D-Minn .) has independently endorsed Bernie Sanders, as have some visible black figures outside of electoral circles, including longtime civil rights activist Harry Belafonte, black intellectual figures like Cornel West and Ta-Nehisi Coates, and a number of activists linked to the #BlackLivesMatter movement.

On the one hand, it is difficult to see the endorsements Sanders has acquired as the kind likely to be particularly helpful to him among black voters. His endorsers have generally not made clear pro-Sanders racial policy arguments for him. Some, like Belafonte, have pitched Sanders as simply aspirationally right, representing “a moral imperative” and a “certain kind of truth.” Others, like West and former NAACP president Ben Jealous, are framing their Sanders support far more in terms of reasons they question Clinton.

On the other hand, the dissensions may be doing political work that could ultimately be even more consequential than the Clinton endorsements. By propping open a space for open debate about candidate support in black communities, a divided black elite can prevent the solidification of what recent work by Ismail White, Chryl Laird and Troy Allen call a “norm of black political behavior” in this election. According to White et al., when ideas of what political choices are in the interest of African Americans as a group become crystallized norms — well-defined and broadly understood — the social location of many black Americans in black spaces, from neighborhoods to churches to fraternal organizations, becomes a social mechanism for encouraging norm-adherent political behavior.

The larger and louder the black elite dissension on Clinton versus Sanders, the less clear it becomes that supporting a particular candidate is something that black voters should do for the interest of blacks as a group. In turn, the less likely it becomes that the social dynamics of black communities will be leveraged to be sure black voters turn up and register their support.

Consider what White, Laird and Allen were able to demonstrate about the norm of black support for President Obama in 2012. Their series of studies provided small cash payouts, quite typical in behavioral experiments, to support Mitt Romney’s campaign rather than Obama’s. The team repeatedly found that black subjects were uniquely willing to take the payouts and support Romney when they were confident that their black peers would not observe their choices. (Rest assured this was all fictitious support, though it plausibly seemed real within the study. Subjects were also all debriefed about the fiction at the end of the study.)

When their choices were made in conditions that implied black peers would know their choices, however, the black respondents stuck to the Obama-supporting norm. But the team also found that they could not use the same sort racialized social pressure to encourage voters to defect from that norm. Witnessing black peers supporting Romney (planted by the researchers — a technique called “using confederates”) did not encourage the black respondents to do the same.

So here’s the rub of the dissenters in the Clinton-Sanders black leader endorsement round-up. In the short run, with electoral contests looming where black voters absolutely matter, such dissension may well push both candidates to address issues of race more than they otherwise would. Thursday night’s Democratic debate saw both candidates take seriously their need to answer questions on issues of race. We’re witnessing discussions of issues like mass incarceration that seem unlikely to have materialized without the sense of competition that a divided black elite implies. But without the development of a norm-inducing consensus among black leaders, the Democratic nominee — whomever it may be — stands less likely to count on the black community dynamics that helped to deliver the record turnout of black voters that helped seal the Obama victories.