New York (CNN Business) Senator Elizabeth Warren wants regulators to keep Wells Fargo in the penalty box until the bank replaces CEO Tim Sloan.

In a letter to the Federal Reserve on Thursday, Warren argued that Sloan, a three-decade Wells Fargo veteran , is "deeply implicated in the bank's repeated and egregious misconduct."

Warren, a Massachusetts Democrat who's said she's considering a run for president in 2020 , urged the Fed to keep the asset cap it placed on Wells Fargo intact until Sloan is removed. The sanctions prevent Wells Fargo from growing its balance sheet, a harsh restriction for a bank during a booming economy.

The Fed's sanctions, handed down in February, require the bank to take a series of steps before the penalties are lifted. Warren argued that Wells Fargo can't possibly satisfy those requirements with Sloan in charge because he was a senior executive when the trouble occurred.

"Mr. Sloan has served as CEO, CFO and COO as Wells Fargo has engaged in this persistent and widespread mistreatment of customers and employees," Warren wrote.