California is a big state with a long history of citizen legislating through ballot initiatives. So it’s little wonder that all but one of the most expensive ballot initiatives in the last 14 years have taken place in the Golden State: There are big corporate interests on both sides, and they’re willing to spend money to tilt the playing field in their favor.

Check out the most expensive ballot initiatives since 2000, data courtesy the Ballot Initiative Strategy Center:

Propositions 94, 95, 96 and 97, which voters decided in 2008, sought to expand the number of Native American casinos. The initiatives, all of which passed, allowed the Pechanga Band of Luiseno Mission Indians, the Morongo Band of Mission Indians, the Sycuan Band of the Kumeyaay Nation and the Auga Caliente Band of Cahuilla Indians to build their own gambling facilities. All told, the two sides spent a whopping $172 million on the ballot campaigns.

Proposition 79 would have provided prescription drug discounts to low-income California residents. Voters defeated the 2005 measure by a 39 percent to 61 percent margin, but not before the two sides spent a combined $163 million.

Proposition 87, which failed by a 45 percent to 55 percent margin in 2006, would have established a $4 billion fund to reduce petroleum consumption. The two sides spent a total of $155 million campaigning.

Proposition 32 would have prohibited unions from deducting funds from worker paychecks for political purposes. It failed by a 44 percent to 56 percent margin in 2012, but not before unions and corporations spent a total of $149 million.

That same year, California voters ratified Proposition 30, which created a temporary tax on high-income earners to fund education. The sides spent $148 million on that measure, though it’s fair to point out that some of the pro-Prop. 30 money also advocated against Prop. 32.

In 2008, California voters passed Proposition 8, which restricted marriage to a union between a man and a woman. Pro-traditional marriage advocates and gay marriage supporters combined to drop $106 million on the campaign.

Maryland voters approved Question 7 in 2012, a measure that expanded gambling in the state. Two mega-corporations involved in the gambling industry spent a combined $95 million fighting for Maryland votes.

A medical malpractice reform measure on the ballot this year in California has the potential to join the list. Doctors and insurance companies will line up on one side, with trial lawyers on the other. That’s a potent, and expensive, clash of titans.