Question: An increase in interest would cause how much of an increase in cost due to our nearly $20 Trillion National Debt? We are locked in a nice box, we are.
If interest rates were allowed to freely float they would have skyrocketed during the 2008 crisis. That would have crashed credit markets, ruined urban finances which were already weak, and cost the economy a terrible year. But, it would have brought bargain hunters and the prudent back into the market. It would have shaken out the cobwebs and forced cities into bankruptcy. It would have reset the political clock.
Instead we have a crony managed economy where politicians work to maintain the status quo. 12 people decide interest rates for a nation of over 300 million. Like a river wanting to flow our massive economy is jumping the banks designed by central planners who don't know the future any better than you or I do.
Sadly, there isn't a front runner willing to reduce government's role in the economy. All governments are socialist institutions. The Founders knew this implicitly even though they didn't have the language to name it. If you don't keep government small by reach and size, then you get European socialism (monarchism/aristocracy/oligarchy - it's all the same essentially), eventual collapse and tyranny.
The problem is government, but half the country believes a little more poison is good for the body.