"Senator Obama shares the values of UMWA members and our families. He understands and will fight for the needs our members have today and the hopes our members have for a secure future for themselves and their families," union president Cecil E. Roberts said, according to the Associated Press.
The Mine Workers had initially endorsed John Edwards, who subsequently dropped out of the Democratic race and last week backed Obama.
"Senator Obama will fight to preserve American jobs, not ship them overseas in greater and greater numbers," Roberts added. "Senator Obama will make sure that the nation's mine safety and health enforcement agency actually enforces the law, instead of coddling mine operators who repeatedly and willfully violate the law."