Three mystery mega-donors helped fund Karl Rove’s $300 million Republican campaign spending in 2012 with donations topping eight figures. Who are these mystery donors? Because Rove's nonprofit is free to withhold information on its donors, we may never know.

According to tax documents released Monday, Crossroads GPS, a nonprofit arm of Rove’s American Crossroads Super PAC, received three eight-figure checks in 2012 alone, all from anonymous donors who do not have to be identified publicly due to tax laws.  

The document reveals that Crossroads GPS received a total of $179.7 million in donations in 2012 and spent $188.9 million in the same year. Fifty-three of its 1,545 donors contributed more than $1 million, and three of those donations exceeded eight figures – in gifts of $22.5 million, $18 million and $10 million. All in all, 291 of Crossroads GPS’ donors contributed more than $5,000 apiece in 2012.

Because Crossroads GPS is a 501c nonprofit, all identifying information on donors who contributed more than $5,000 has been redacted. Such nonprofits must report their annual spending, but have the privilege of keeping any and all donor information private.

Meanwhile, the group’s sister Super PAC, American Crossroads, both raised and spent a total of $117 million throughout the 2012 election cycle. All together, the two groups raised a total of $325 million to fund and promote various Republican campaigns in 2012. The number is less than the Republican National Committee’s fundraising of $390 million, but well above the Democratic National Committee’s $290 million raised in the same time frame.

Crossroads GPS spent $74.5 million on advocacy during the 2012, while another $74.2 million went directly to funding political campaigns. An additional $35 million went to grants for other nonprofits, including Americans for Tax Reform, Americans for Job Security, and the Center for Individual Freedom. The latter two are also 501c nonprofits that are allowed to hide their donors.

The tax documents also revealed that Crossroads GPS President Steven Law took home $528,000 for his 48-hour work week with the company, as well as an additional $99,562 from related groups, presumably from serving as president and CEO of American Crossroads. Meanwhile, Crossroads GPS Treasurer Caleb Crosby received $56,000 for a 20-hour work week, as well as an additional $56,000 from American Crossroads, where he also serves as treasurer.

Though Rove, who President George W. Bush's political mastermind, founded Crossroads GPS with Ed Gillespie, he was not paid anything by the group in 2012 and does not appear listed as a Crossroads GPS officer.