Big donors absent from Obama campaign

US President Obama's re-election campaign is shifting into high-gear, as he raises millions of dollars for his political coffers, but the size of the campaign donations have dropped significantly.

US President Obama's re-election campaign is shifting into high-gear, as he raises millions of dollars for his political coffers.

But the size of the campaign donations have dropped significantly.

This time in 2008, Obama had 23,000 donors who offered donations of $US2,000 or more.

Today, the campaign contributions are half the amount.