The Kochs come in 48th, giving just $27 million to Republicans.
When it comes to money in politics from organizations as opposed to individuals, Democrats easily get the majority of it . . . mostly from the unions both public and private. Almost all the top 20 contributors to Democrats are unions, contributing $1.4 billion total with unions accounting for $1 billion of that. The top 20 contributors to Republicans can't even crack the $600 million level.
Open Secrets has the data, here.