Just from that chart I linked, Carter lost it, 47% to Ford's 52% while winning the presidency.
The last time a Democratic candidate won the majority of the white vote was in Lyndon B. Johnson in 1964, though I don't know what the break down was. President Johnson signed into law the Civil Rights Acts of 1964 and 1968 as well as the Voting Rights Act.
While in the Senate, Johnson helped pass the Eisenhower's Civil Rights Act of 1960 established federal inspections and penalties for voter registration, precursor to LBJ's Voting Rights Act.
In the last 30 years, blacks have voted in the high 80th to low 90th percentile for the Democrats. With Obama outperforming Gore in that demographic by 5%.
In the same time period Obama has also outperformed previous Democrats for the white vote, in fact, Obama is tied for 2nd with Clinton behind Jimmy Carter in white vote percentage.
Implying all blacks voted along racial lines is bullshit, when in reality the racial line fell their way. It's akin to saying whites only voted for white presidents 43 out of 44 times, but whatever, keep your racist agenda up. The fortunate side effect of Obama drawing out all the racists, is at least they're out of the closet and can be summarily ridiculed.
Compared to Gore (because he was the last democrat to win the popular vote) in 2000, Obama won 5% more blacks, and 5% more hispanics, 8% more asians, and 1% more whites. Tell me again who's voting along the race line?