Fundraising for the presidential campaigns has surpassed the $1 billion mark, USA Today reports.
In the first election since the rise of candidate-aligned super PACs raising unlimited sums, and the first since 1972 that is financed entirely by private money, the biggest spending is yet to come.
Obama is appealing to donors with increasing urgency as he trailed his opponent for the second month in a row in June: Obama and his allies raised $71 million that month, just short of the $106 million raised by Romney and the Republicans.

