It's an idea whose time has long past come. In my mind, the largest problem facing our political system today is career politicians who serve for multiple decades. It serves no interest other than self interest to maintain a place in office so long, as it makes it far more difficult for new, younger members to enter the political arena. Those that do nationally are almost universally stepping up from statewide elections, and they from local or county political systems. How much democracy can one have if the choices are only those that have spent their entire lives in politics?
My solution isn't a perfect one, I'll be the first to admit. But it's far better than the current system. I propose a maximum of 12 years total for all national level politicians. That means you could be a House member up to 6 times, a Senator twice, or the President twice with some change. If nothing else, it'd get more people involved in the political system. And honestly that's the reason why current politicians won't go for it. It'd challenge their free ride. It'd force them to work, because even if they did nothing, they'd only be able to do that nationally for a decade.