So Trump's latest interference in free market capitalism is his threat to cap credit card rates at 10%.  He and Elizabeth Warren make strange political bedfellows.  

It may be well meaning in pushing back against 20 % and higher charges on credit card debt but if implemented it will backfire.  Those who run credit card debt and pay those high rates are the most likely to default on their debt.  THAT is why they get charged high rates.  

If a cap of 10% is put on credit cards then those companies will implement tighter standards for people who want credit cards.  And so, the higher risk customers won't get a credit card.  They would have to go on the black market for loans.