New York Senator Kirsten Gillibrand has proposed turning post offices into bank branches. She, and others before her, say that postal banking would end predatory lending overnight. But the idea has not gained much traction.

The proposed legislation is laden with ideas aimed at a liberal base. Small, low-fee loans to get rid of payday lenders, remittance services so immigrants can cheaply send money home, low-cost checking accounts to compete against big banks.

Turning the post office into a bank is not a new idea. Senators Bernie Sanders and Elizabeth Warren made similar proposals in 2014 and 2015. Political activist Ralph Nader boasted the idea in 2011, but it never took off, in part because of opposition from the financial services lobby. There’s also political discomfort with the idea of the U.S. government in the business of loaning people money. Even the post office dismissed the idea.

Speaking in 2014, Postmaster General Patrick Donahoe, said, “The key thing for any successful business is to work within their core. We don’t know anything about banking. We’d be perfectly interested in talking to someone who would want to use the facility to accept a deposit, but to set a banking system up and lend money to the unbanked. We don’t know anything about that.”

According to the FDIC, about 7 percent of the country doesn’t have a banking account. That number has been steadily falling.