Clinton campaign falters as superdelegates back Obama

Barack Obama has almost tied with Hillary Clinton in the crucial superdelegate count that she once dominated, with the slew of new support offering one of the clearest signs yet that her Democratic White House bid is nearly over.

After a gruelling duel marked by bouts of acrimony and bitterness, the Democratic race for the presidential nomination entered its final weeks, if not days, with electoral mathematics the deciding factor.