In March 2009 Bernie Sanders introduced legislation that would cap most interest rates at 15 percent
In March 2009, one senator we spoke to -- Bernie Sanders, an Independent from Vermont -- introduced legislation that would cap most interest rates at 15 percent. He was able to bring it to the floor for a roll call vote two months later, when debate on the credit card bill was in full swing. It was shot down 33-60.
https://www.pbs.org/wgbh/pages/frontline/creditcards/themes/caprates.html
For much of human history usury laws have been in place -- rules that prohibit charging unreasonably high rates of interest on loans. Christianity, Islam and Judaism all prohibit the practice because usury takes advantage of others and is unfair. For many years the United States had state usury laws which kept interest rates low.
Then came the 1978 Supreme Court decision Marquette v. First of Omaha Service Corp., which blew the lid off interest rate ceilings. The court ruled that rates could be decided based not on where the borrower lived, but where the credit decision was made -- essentially, banks could "export" their interest rates by setting up operations elsewhere. In states like South Dakota and Delaware, which eliminated interest rate caps, banks set up credit card operations, loaned out billions and credit card usage soared.
https://www.pbs.org/wgbh/pages/frontline/creditcards/themes/caprates.html