"The California Right to Know Genetically Modified Food Act” known as Proposition 37 will require food manufacturers to label food with genetically modified ingredients (GMOs). If the bill passes, it will be the first law in the United States that required GMO labeling. Some European countries already mandate GMO labeling, but efforts to pass legislation in the United States have met resistance. Over a dozen other states have failed to pass proposed labeling laws. Food manufacturer argue that the bill is unnecessary because GMO are safe. They believe labeling will drive up food costs and will confuse consumers. Proponents of the legislation assert that consumers have a right to know what is in their food. Corporations that produce genetically modified foods point to hundreds of studies that show that they are safe. California voters will soon make a choice about GMO foods labels, and both sides are spending millions of dollars to influence their decisions. The result of the ballot initiative will reverberate throughout the nation.
What is the main idea of this passage?