The ease with which money flowed into the coffers of conservative advocacy groups that sought to deny President Obama reelection is underscored in a draft tax filing for the twin Crossroads organizations that the Wall Street Journal got a peek at Thursday.

One single donor ponied up $22.5 million of the $180 million haul raised by the tax-exempt group Crossroads GPS in 2012. Because the organization is set up as a social welfare advocacy organization, not as a political committee, it is not required to disclose the names of its benefactors.

Crossroads GPS and its sister super PAC, American Crossroads, were co-founded by Republican strategist Karl Rove in 2010, shortly after a series of federal court decisions opened the door to unlimited political spending by corporations and deep-pocketed individuals.

Together, the two groups brought in $325 million during the most recent two-year election cycle.

Another major conservative advocacy group, Americans for Prosperity, which has been supported by the billionaire industrialists Charles and David Koch, raised more than $190 million together with its related foundation in the 2012 cycle, as previously reported. (AFP spent $122 million of that last year alone, according to new documents filed in Colorado, first reported by the Center for Public Integrity.)

That means that donors coughed up more than half a billion dollars just for the Crossroads and AFP outfits, only to see Obama reelected.

It remains to be seen whether conservative patrons will be as generous in the coming cycle. But early signs indicate that many are taking a more cautious approach toward their political investments.