Did Dewey lose in 1948 because he neglected the black vote?

[zorkpolitics]

Unlike recent elections, Republicans typically had a pretty high percentage of the African-American vote in the first half of the 20th century.  Although Dewey had the best record on civil rights of any governor at that time, he ignored pleas from African American Republicans to campaign on his record.  In the end though he lost nationally by 4%,,Truman won the election because he carried CA and OH by less than .25%.  If Dewey had fought for the black vote he might have blocked Truman's victory and sent the election to the House of Representatives.
Why didn't he raise the civil rights issue?

[zorkpolitics]

I'm not sure, but maybe he feared losing the Upper South Republican vote? (That would've been pretty dumb though, he didn't stand a chance to carry anything there as it was).
Also, could you expound on his Civil Rights record?

In 1941, when he was elected governor of New York State. Dewey kept his promise by setting in place reforms, including the first statewide civil rights legislation in the nation, establishing the first state agency to eliminate discrimination in employment.

also under Dewey's leadership, the Republicans enacted a platform at the 1948 convention which called for expanding social security, more funding for public housing, civil rights legislation, and promotion of health and education by the federal government.


see:
http://www.nps.gov/elro/glossary/dewey-thomas.htm
http://en.wikipedia.org/wiki/U.S._presidential_election,_1948