By the end of the recall election, Walker had a national network of conservative donors and groups supporting him. Nearly 300,000 people donated to his recall campaign, which garnered roughly $37 million. Two-thirds of the contributions came from outside Wisconsin. Walker, or the conservative causes he supports, are also supported by conservative donors and groups including Michael W. Grebe, Diane Hendricks, and the Bradley Foundation, founder of the Wisconsin Policy Research Institute and the MacIver Institute; and David H. Koch and Charles Koch, initial funders of Americans for Prosperity.