The New York senator is making the case to superdelegates, the party leaders and elected officials who will weigh in on whether she or rival Sen. Barack Obama, D-Ill., should be at the top of the ticket.

The Wall Street Journal reported Saturday after her win in Pennsylvania, Clinton's campaign began saying "more people have voted for Hillary than any other candidate."

Analysts say Obama could close Clinton's lead in the popular vote May 6, when Indiana and North Carolina hold their nominating contests.

But even if Clinton remains ahead in the popular vote, Colby College political scientist Tony Corrado noted the popular vote has never been used to nominate or elect presidents.

But because Clinton is trailing Obama by 125 delegates, Corrado said using her lead in the popular vote to argue her case to the party's superdelegates is "the only number that works for her."