Even after that, Republican nominees continued to get a large slice of the black vote for several elections. Dwight D. Eisenhower got 39 percent in 1956, and Richard Nixon got 32 percent in his narrow loss to John F. Kennedy in 1960.
But then President Lyndon B. Johnson pushed through the landmark Civil Rights Act of 1964 (outlawing segregation in public places) and his eventual Republican opponent, Sen. Barry Goldwater, opposed it. Johnson got 94 percent of the black vote that year, still a record for any presidential election.
The following year Johnson signed the 1965 Voting Rights Act. No Republican presidential candidate has gotten more than 15 percent of the black vote since.
Footnote: Younger African American voters have been edging away from the Democratic Party in recent years. David Bositis of the Joint Center notes "a fairly long-term pattern of decreasing identification with the Democrats by younger African Americans." Of course, it remains to be seen what the 2008 campaign will bring.