The hopes of a younger guard of black politicians were not realized in Tuesday's primary in Georgia; two challengers gave Rep. John Lewis (D-5th District) his first primary challenge in 16 years but failed to come close to defeating Lewis, let alone pull him into a runoff. Their beef with the longtime civil rights icon: his initial endorsement of Hillary Clinton over Barack Obama, which they argued showed he was "out of touch."

Similarly, the primary challenge to white incumbent John Barrow (D-11th) from state Sen. Regina Thomas, who is black, also had racial considerations; the district is 45 percent African-American, and Barrow is quite conservative. But Barrow had the endorsement of Obama and sailed through his renomination fight. One lingering question for Barrow, who defeated his GOP rival by just 864 votes in 2006: will his embrace of Obama, which helped him on Tuesday, hurt him in November with conservative, rural whites?

At least three other Democratic incumbents — two black, one white — are facing potentially difficult primaries in the next two months, and in two of them race is clearly a factor.

 

On Aug. 5, Rep. Carolyn Cheeks Kilpatrick is being challenged by state Sen. Martha Scott and former state Rep. Mary Waters in Michigan's 13th District. Here, however, the issue is less about race — all three candidates are black — than it is about Kilpatrick's son: Kwame Kilpatrick is the under-siege mayor of Detroit who has embarrassed even longtime supporters with his defiant refusal to step down in the wake of a personal scandal. Waters in particular is lambasting Congresswoman Kilpatrick for her unflagging defense of her son (compare, if you will, the tongue-lashing Rep. Jesse Jackson Jr. gave to his dad following his surgical suggestion for Obama).

Two days later, Rep. Steve Cohen (D-Tennessee 9th) — who is white — is facing a challenge from four black challengers, who argue that Cohen should not be representing a district that is 60 percent African-American. Two years ago, a similar situation (a field of Cohen and multiple black candidates) enabled Cohen to win the primary with just 31 percent of the vote. Cohen, however, is strong on black issues, and he sports the endorsement of many black leaders, including House Ways and Means chair Charles Rangel of New York.

And in September, in Brooklyn's 10th District, incumbent Democrat Ed Towns is under a well-financed assault from fellow African-American Kevin Powell, who recently benefited from a fundraiser held by comedian Dave Chappelle. Like John Lewis, Towns' sin was endorsing Clinton over Obama for president — but in his case, he may have thought that bucking his state's powerful senator was more difficult politically than snubbing Obama. We'll see on Sept. 9.