WASHINGTON — Stung by robberies in California, Colorado, Washington and other states, the cannabis industry is pressing Congress to change federal banking laws so that its retailers no longer have to carry and process large amounts of cash.

Yet lacking the lobbying muscle of their adversaries, the industry hasn’t gained much traction on Capitol Hill, leaving cannabis business owners and their employees vulnerable to thefts and violent crime.

Republican lawmakers from pot-unfriendly states have sidelined legislation in the House and Senate that would allow marijuana businesses to conduct transactions with federally regulated banks. These also include state and community owned banks that are part of the Federal Reserve System.

In another blow for the industry, Attorney General Jeff Sessions last month made it easier for federal prosecutors to enforce federal marijuana laws in states that had legalized the drug. The announcement caused stock prices for pot companies to plunge, and prompted many financial institutions to become even more wary of conducting business with marijuana enterprises.

Michael Correia, a lobbyist for the National Cannabis Industry Association, said there are strong law-and-order arguments for allowing marijuana businesses to bank like others do. They’d no longer need to conduct transactions in cash, including paying employees, could more easily pay their taxes and could separate themselves from the illicit marijuana market, he said.

But according to Correia, the Republican leadership in Congress has shown no interest in even holding hearings on the SAFE Banking Act, legislation that would free banks to conduct business with state-approved marijuana growers and retailers.

“It is very frustrating,” said Correia, who previously worked for U.S. Rep. George Radanovich, a California Republican who retired in 2010. “The leadership of Republican Party are old school people and do not support this legislation. We haven’t gotten any movement to this point.”

For the cannabis industry and states that have legalized marijuana, the stakes are considerable. Cannabis businesses generate about $8 billion in annual revenues, a figure that is projected to reach $24 billion by 2025, according to New Frontier Data, a D.C.-based analytics company that monitors the industry.