And together, supporters and opponents of the two props on the ballot have raised more than $400 million.ĭANIEL WALLACH: California is poised to basically be the gold standard and the holy grail of U.S. MARZORATI: One ballot campaign is the most expensive in U.S. Written and funded by big out-of-state gambling. Tribes overwhelmingly oppose Proposition 27. GUY MARZORATI, BYLINE: For months, it's been hard to watch TV in California without hearing about sports betting. From member station KQED, Guy Marzorati reports. The campaign has sparked historic spending from tribal gaming groups and national betting companies. California voters will see a pair of dueling initiatives to legalize it there. The largest expansion of sports betting in America is on the ballot this November.