Hillary Clinton tried to make Louis Farrakhan an issue when she ran against Barack Obama in 2008. The Nation of Islam leader—infamous for calling Judaism a “gutter religion”—had praised the future president as “the hope of the entire world.” In a February debate, Mrs. Clinton demanded that Mr. Obama reject Mr. Farrakhan’s support, insisting: “There’s a difference between denouncing and rejecting.” Mr. Obama obliged and added: “There’s no formal offer of help from Minister Farrakhan that would involve me rejecting it.”

Three years earlier, Mr. Obama posed for a photo with Mr. Farrakhan at a Congressional Black Caucus gathering. The photographer, journalist Askia Muhammad, told the liberal site Talking Points Memo that a CBC staffer contacted him “sort of in a panic” about the photo. “I promised and made arrangements to give the picture to Leonard Farrakhan, ” Louis Farrakhan’s son-in-law and chief of staff. But he kept a copy, which he released last week.

Mrs. Clinton might have become president had the photo come out a decade earlier. It isn’t clear from the photo to what degree Mr. Obama was associated with Mr. Farrakhan. But the Congressional Black Caucus’s association is scandalous. Its members have met with Mr. Farrakhan on at least one other occasion.

On Jan. 13-14, 2006, the House Financial Services Subcommittee on Housing and Community Opportunity held hearings in New Orleans and Gulfport, Miss., on the federal government’s response to Hurricane Katrina. After the New Orleans hearing, at least four CBC members headed to St. Augustine Church to meet Mr. Farrakhan, who had attended part of the hearing.

In a video posted to YouTube in 2009, Reps. Maxine Waters and Barbara Lee of California, Al Green of Texas and William Jefferson of Louisiana can been seen exchanging hugs and handshakes with Mr. Farrakhan, then talking with him about coordinating their public responses to Katrina.

After praising the representatives for their performance at the hearings, Mr. Farrakhan says: “Tell me how I can be of service.”

Ms. Waters responds: “I think we need to get together and talk about how we’re going to put New Orleans on the national agenda.” (I emailed Ms. Waters’s press secretary Tuesday to ask if such a meeting ever took place. The press secretary replied that Ms. Waters was traveling and unable to answer.)

Mr. Jefferson, who represented New Orleans, explains to Mr. Farrakhan how difficult it is to get colleagues from elsewhere in the country interested in Katrina relief.

Mr. Farrakhan tells the group that “this is where the battle lines need to be drawn,” but “without a force that makes, that creates the political will,” their efforts would be wasted. The video ends with Mr. Farrakhan describing Katrina as a judgment from God, akin to the biblical plagues.

Mr. Farrakhan went much further in a sermon titled “A People Robbed and Spoiled,” which he delivered that weekend at St. Augustine Church. “Your problem is you are not now nor have ever been a citizen of the United States of America,” he told the congregants. “You are a slave to white America. It bothers me to hear you crying how you’re an American but they treat you like a slave. It bothers me that you are willing to fight and die for something that is not willing to sacrifice nothing for you.”

The Southern Poverty Law Center classifies Mr. Farrakhan as a “black separatist” and the Nation of Islam as a hate group. Alan Dershowitz reacted to the Obama-Farrakhan photo by saying he would not have campaigned for Mr. Obama had he known about it: “There must be zero tolerance for anti-Semites, whether they are David Duke or Louis Farrakhan. No one should associate with either. The suppression of that photo is disgraceful.”

He has a point. If Republican lawmakers were holding strategy sessions with Mr. Duke, their party would rightly be held to account. Why shouldn’t the Democrats and the Congressional Black Caucus be held to the same standard?

Mr. Bier is an accountant and freelance writer.