If you want to see this chart a different way, you can check out Jim Geraghty's version at National Review. Prepare to see a lot of blue donkeys, because 20 of the top 32 donors lean Democrat, while only 6 lean Republican. The rest are on the fence.
Not only that, if you factor in all the indirect benefits the Democrat Party gets from the non-profit sector, left-wing activism, public and private sector unions, Wall Street banks, universities, and superfund contributors, it has been estimated by Dr. David Horowitz and Jacob Laksin in their book The New Leviathan that the Republican Party is outspent in politics by a factor of 7-to-1.
Bear this in mind when the left goes off on a tirade about the Koch Brothers bogeymen, who come in 59th on a list of top contributors. Public and private sector unions leave the Koch Brother's measly $18 million over 25 years in the dust.