Even Clinton's most energetic boosters expressed exhaustion by the call to raise more money. "I'll tell you, after a year of doing this, it's like asking me to run a half-marathon after I've run a marathon," said Mark A. Aronchick, a co-chairman of Clinton's Pennsylvania campaign, who is organizing five fundraisers over the next eight days.
Clinton, too, had a hint of resignation in her answer to reporters asking whether she is now being outspent "two to one" by Obama. "Sometimes three to one, four to one, five to one," she said with a laugh. "I'm getting used to being outspent."
Obama's immense cash flow -- he has raised more than $240 million to Clinton's $175 million -- allows him to compete as aggressively in the final primary contests as he did in the early days of the race. He is vastly outspending Clinton in Pennsylvania, with $3 million in television and radio ads, including a Spanish-language TV ad airing in the Philadelphia area, compared with an estimated $500,000 that Clinton is spending in the state, which will hold its primary on April 22.