The Republican Governors Association benefited from a number of sizable contributions from deep-pocketed individual and corporate donors over the last few months, driving a record $31 million fund-raising haul in the third quarter.

The donations, itemized in a 268-page report filed with the Internal Revenue Service, seemed to encapsulate the Republican Party’s success this year in collecting huge checks from conservative donors and corporations through third-party groups, thanks to a favorable political environment and the Supreme Court’s easing of restrictions on corporate political spending.

The association, led by its chairman, Gov. Haley Barbour of Mississippi, out-raised its Democratic counterpart by more than three to one from July 1 to Sept. 30. With $31.5 million in the bank, the group had more than twice as much cash available for the final stretch of the midterm campaign.

In sharp contrast to the party-affiliated committees in the House and Senate, the governors associations are set up as so-called 527s, able to accept contributions of unlimited size from individuals and corporations. It is in the realm of these large, unrestricted donations that Republicans have built a huge advantage this year in terms of independent group spending.