Despite being surrounded by the world’s most famous casinos as well as slot machines in almost every corner convenience store, Nevadans love playing the numbers. But the state is one of just seven that still prohibit lotteries. Now, faced with a budget deficit of about $3 billion and armed with opinion polls showing that more than 70 percent of residents support a lottery, state lawmakers in Carson City are considering a measure that would begin the lengthy process of legalization.

But opponents, such as legislators who call it a regressive tax that preys on the poor and owners of casinos off the Las Vegas Strip that cater to local residents and fear the competition, say they will work hard to ensure that does not happen.

“I’m getting letter after letter from people who want a lottery, and they should be able to have one,” said Assemblyman Paul Aizley, Democrat of Las Vegas, who introduced a resolution to allow a lottery, which the Assembly passed last week by a vote of 31 to 11.

“The current budget problem we have is not an instant, only-now problem,” Mr. Aizley said. “It will be with us for a while, so anything that can generate more revenue is worth considering.”

The bill is before the Senate, where its chances are unclear, but the majority leader, Steven A. Horsford, a Democrat from the Las Vegas area, is a longtime supporter of a lottery. Mr. Horsford conceded, though, that a lottery was not the solution to the state’s budget woes.

“To me,” he said, “it’s a small piece of a whole. This is not how we9 9re going to get out of a $2 billion hole.”

A spokesman for the California Lottery, Alex Travero, said no one tracked the percentage of tickets sold to Nevadans, but Mr. Travero noted that last year the Primm outlet sold an average of $250,425 in lottery tickets per week and that the second-highest sales outlet, Gold Ranch, 11 miles west of Reno, Nev., averaged $121,020 per week.

Joanne Sargenti was waiting in line outside Primm Valley Lotto. “Last week,” Ms. Sargenti said, “the line was out to here in the parking lot, all Nevada plates, because MegaMillions was up there. I would much rather play in town if I could.”

Instead, Ms. Sargenti drives here from Henderson, a Las Vegas suburb, every Tuesday to buy $200 worth of tickets.

Assuming that lottery supporters prevail, Nevadans could not hope to buy tickets before 20 13 because altering the state’s Constitution would require that Mr. Aizley’s bill pass the Legislature twice and be approved in a statewide referendum.

Mr. Aizley said he had no revenue estimates for a Nevada lottery, but Matthew Sweeney, the author of a book titled “The Lottery Wars,” said lottery states with populations similar to Nevada’s realized about $60 million a year in profits.

Nevada’s profits could be higher, Mr. Sweeney said, because the 40 million tourists who visit Las Vegas each year enhance the market far beyond the state’s 2.6 million residents.

“It’s just so inefficient because for every $1 that is collected, the state only keeps about 35 percent,” Mr. Sweeney said. “But Nevada has to be so accustomed to gambling that I can’t imagine there would be opposition.”

But opposition there is, some of it similar to that in other states where studies have shown lotteries to be regressive taxes paid disproportionately by poor people.

State Senator John J. Lee, Democrat of Las Vegas, who has long argued against a lottery, cited his pervasive fear that “a mother would go into the store to buy two gallons of milk and a loaf of bread but play the lottery instead and leave with one gallon of milk.”

An advocate for the homeless, Linda Lera-Randel El, said she had not decided how she felt about a lottery, but she noted that stores of the type referred to by Mr. Lee typically offered banks of slot machines.

“No matter where you go here, if you’re washing your clothes or buying groceries, you have gambling, so if that same mother is inclined to spend $1 she can’t afford on lottery tickets, she’s already changing it into quarters and spending it on video poker instead,” said Ms. Lera-Randel El, executive director of Straight From the Streets. “Don’t s ay we can’t have a lottery because poor people are so stupid they can’t handle it.”

Casino owners who oppose a lottery offer other reasons. Lori Nelson, a spokeswoman for Station Casinos, which owns 18 casinos geared to Nevada residents, asked, “Why would you want to have the state compete against its largest industry?” And Rob Stillwell of Boyd Gaming, owner of seven Las Vegas properties, said lotteries, which “can operate as kiosks” with relatively few employees, had an unfair advantage over casinos, which have the expense of infrastructure, amenities and a substantial payroll.

Mayor Oscar B. Goodman of Las Vegas, a lottery supporter, suggested something that might allay casino owners’ concerns.