The United States Supreme Court on Monday ended a 26-year ban on betting on professional and college sports. The court’s decision permits state officials to pass laws permitting books to open on sports such as football, basketball, baseball and other games. In the coming months, those officials will also consider where bets can be placed: casinos, horse racing tracks, betting centers, stadiums, online, or from mobile phones. Supporters of the decision said legal betting could sharply increase income for states and the gambling industry. And they pointed out illegal sports betting is common. The American Gaming Association reported that Americans already place about $150 billion a year on bets. Opponents of the decision include major sports groups, such as the National Football League.