Democrat Terry McAuliffe will be Virginia’s next governor, and it only took one California billionaire to get him there.

Billionaire San Francisco hedge fund manager Tom Steyer donated more than $8 million to McAuliffe’s campaign, Politico reports, over three times more than the initially reported contribution. Steyer’s donations alone matched funds raised by the Republican Governors Association, the deep-pocketed group that raised the most money for McAuliffe’s opponent Ken Cuccinelli.

“It is more money, on a per-vote basis, than the famously prolific conservative donors Sheldon and Miriam Adelson spent in the 2012 presidential election,” Politico writes of Steyer’s donation.

Much of the $8 million came from Steyer’s own $1.5 billion fortune, distributed through his political action committee, NextGen Climate Action. As its name suggests, NextGen Climate Action is dedicated to championing environmental causes and specifically pushes for clean, renewable energy. So where exactly did that $8 million in funding go? According to Politico, largely toward attack ads designed to mock Cuccinelli for his backward views on environmental issues.

“Steyer paid for $3.1 million in TV advertising, $1.2 million in digital ads, 12 different pieces of campaign mail, a field program that hit 62,000 households on get-out-the-vote weekend and even a Cuccinelli impersonator who showed up at public events carrying a briefcase of mock cash to attack the Republican’s ethics,” Politico writes.

After McAuliffe’s narrower-than-expected win over his Republican opponent, Steyer believes that $8 million was money well-spent.

“One of my friends who is a Democratic governor and knew what we spent said, ‘I think you overspent on this campaign.’ But it turned out we didn’t,” Steyer told Politico. “We kept going with what we originally thought we needed to do for the turnout, which was our whole goal.”

This is hardly the first time that Steyer has contributed his fortune towards progressive political causes. In 2012, Steyer was the lead backer of California’s Proposition 39, a measure he also had a hand in designing. The San Francisco billionaire contributed $21.9 million toward passing the measure designed to close tax loopholes for out-of-state corporations operating in California.

In fact, after retiring from the finance world for good in 2012, Steyer decided to work full-time bankrolling and supporting progressive causes across the country. If there's one person to watch out for in the 2014 elections, it might not be any of the candidates, but Tom Steyer himself.