Obama closes in on Clinton superdelegate total as Clinton fights on

WASHINGTON (CNN) - Sen. Barack Obama closed in Friday on Sen. Hillary Clinton's lead among superdelegates, the Democratic Party officials who hold the balance of power in determining which candidate will be the party's nominee for president in November.

The Obama campaign announced new support from four superdelegates Friday - including one who had been backing Clinton.

Clinton also announced a new supporter, maintaining her superdelegate lead over the Illinois senator, but only by three - the narrowest it has been to date. She led by more than 100 superdelegates at the beginning of the year.

But Clinton is not going down without a fight. She made two pitches to superdelegates Friday arguing that she is the best candidate to lead a Democratic ticket against the Republicans in November.