The Democratic National Committee — in debt and underfinanced a year ago — has poured nearly $30 million into these key states through the beginning of September.
The funding was powered by a surge of six-figure contributions raised by Mrs. Clinton from the likes of James Cameron, the Hollywood director, andGeorge Soros, the retired hedge fund manager, as well as several members of the billionaire Pritzker family.
The Republican National Committee has provided the states with just $11 million, limited by Donald J. Trump’s difficulties in persuading the traditional Republican big-donor base to invest in his campaign.
Like other candidates for federal office this year, Mrs. Clinton can accept only up to $5,400 from any one donor over the course of her campaign. But after the McCutcheon decision, Mrs. Clinton established an agreement last year with the Democratic Party under which she asked her wealthiest patrons to write checks in excess of $300,000, more than double the old limit, to the Hillary Victory Fund, an account made up of the national and state parties and the Clinton campaign.
That amount is a lump sum equal to the total contributions each donor is allowed to give to her campaign and the Democratic National Committee, along with $10,000 to each of the 38 state party organizations now participating in the arrangements.
Because there are no limits on how much money party committees can transfer to one another, most of the state parties have cycled their share back to the Democratic National Committee. The party then moved the cash into a smaller number of battleground states to prepare for Election Day.