The veteran Democrat says the US president has asked her to work with him on legislation to cap credit card interest rates at an annualised 10 per cent for one year, a proposal he pushed strongly in Davos this week. The big banks are gearing up to fight this union of the populist left and right. Legislation will be an uphill battle, but at least the drama is casting a spotlight on historically high credit card rates and the burden they place on working families.