There is not really a verse that says, "Thou shalt not gamble," but Christians and their love for the poor should keep Christians away from lotteries and, I think, lead them to oppose efforts to expand the lottery.
Many studies have been done, but let me point out one study and then share one quote from a well-known community organizer and activist.
This 2008 study from Carnegie Melon explains "poverty's central role in people's decisions to buy lottery tickets." The article goes on to say:
Although state lotteries, on average, return just 53 cents for every dollar spent on a ticket, people continue to pour money into them -- especially low-income people, who spend a larger percentage of their incomes on lottery tickets than do the wealthier segments of society. A new Carnegie Mellon University study sheds light on the reasons why low-income lottery players eagerly invest in a product that provides poor returns...
"Some poor people see playing the lottery as their best opportunity for improving their financial situations, albeit wrongly so," said the study's lead author Emily Haisley, a doctoral student in the Department of Organizational Behavior and Theory at Carnegie Mellon's Tepper School of Business. "The hope of getting out of poverty encourages people to continue to buy tickets, even though their chances of stumbling upon a life-changing windfall are nearly impossibly slim and buying lottery tickets in fact exacerbates the very poverty that purchasers are hoping to escape."...
In the study, the researchers note that lotteries set off a vicious cycle that not only exploits low-income individuals' desires to escape poverty but also directly prevents them from improving upon their financial situations.
A few years ago, then State Senator Barack Obama explained that the lottery is a "form of regressive taxation" and harmful to the poor.
"One of the concerns that I have, obviously, is that a disproportionate number of people who consistently buy lottery tickets tend to be lower-income and working-class people who can least afford it," he said. "Even if they're not compulsive gamblers, they are probably spending money that they don't necessarily have."
Obama also suggested that state lotteries' marketing practices made them complicit in fleecing the low-income crowd.
"Now, we might say that this is their entertainment dollar the same way that somebody else has entertainment dollar and spends it on a movie," he said. "But I think the fact that the state systematically targets what we know to be lower income persons as a way of raising revenue is troublesome.
"I would argue that if you look at it as a whole, in most states across the board, this tends to be a form of regressive taxation, and I don't think it's necessarily the fairest way for us to raise revenue for us in the state," he said.
I agree... so, while someone is going to get rich this week, a whole lot of people are going to get a little poorer. We don't need another "tax on the poor" and we don't need the government supporting and promoting such efforts.