THE organisers of anti-Obama coalition insist most of their money comes from small individual donations. But a few rich backers continue to wield influence behind the scenes. Here are some of those involved.

The Koch brothers Founders of Americans For Prosperity, one of the main groups behind the 9/12 march on Washington, to the tune of more than a million dollars. David Koch is chairman of the group.

He and his brother Charles own Koch Industries, a $90bn company that is the second largest privately owned firm in the US. The reclusive billionaires are long-term funders of conservative causes such as low tax, small government and a resistance to action against climate change. In 1984 they founded the thinktank Citizens for a Sound Economy, from which AFP and its sister group FreedomWorks emerged.

Richard Scaife Another veteran sponsor of free market causes over more than 20 years. Scaife gave Citizens for a Sound Economy more than $2.5m before it split, and continues to fund FreedomWorks. Scaife is the heir of the Mellon banking and oil empire and owns several newspapers. He was a central figure in the loose network of people out to impeach Bill Clinton in the 1990s in what Hillary Clinton dubbed “a vast rightwing conspiracy”.

Steve Forbes The head of the Forbes business magazine empire — with personal wealth of almost half a billion dollars — Forbes is a leading proponent of a flat rate of tax and ran for nomination as Republican presidential candidate in 1996 and 2000. He funds FreedomWorks and sits on the board of its foundation.

Art Pope Pope hails from a wealthy retailing family that owns a nationwide chain of stores, Variety Wholesalers. He is vice-chairman of Americans For Prosperity, to which he has contributed at least $200,000.

— The Guardian, London