DeVos, a multimillionaire, had developed substantial political contacts with the full participation of his wife, former Michigan Republican Party chair Betsy DeVos, despite which, fully 85% of the DeVos campaign's contributions were from DeVos' inheritance. As the 2006 election approached, the DeVos family was listed among the biggest Republican campaign contributors in Michigan. The DeVos campaign spent $42.5 million, at that time the most spent on a gubernatorial campaign in Michigan history. $35.5 million of that total came from DeVos' personal fortune, and was at that time the most spent personally by a Republican candidate running for governor. The Granholm campaign spent $15.7 million. The combined money spent by both campaigns made this election the most expensive gubernatorial election in Michigan history. As DeVos funded his campaign himself, he was not eligible for public funds.