According to this chart at Open Secrets, the unions are heavily outspending their current Alinsky Rule 11 targets, the Koch brothers. Heavily. Of the top 20 groups that donate politically, 10 of them are unions, and all of them tilt heavily toward the Democrats. And four of those 10 unions — AFSCME, NEA, AFT and SEIU — are either outright government unions or represent some portion of government workers. These are your tax dollars, being picked up in the form of forced union dues in the union-dominated states, being used to fund partisan politics. Click to enlarge.
By the way, the Koch brothers come in at #83 on the list, having given just $11 million over the entire run of this chart, which covers 1989-2010. AFSCME alone has given $43 million, or nearly four times as much as the industrialists they are currently demonizing.