I would like everybody to have the ability to choose their own system for delegation. A ranking system is the just one of the simplest way to give more options.
Every person should be able to have different delegates for different types of votings. She may want to delegate to one party for another party for school, a third party for nature preservation, and so on.
She may want to have diffrent priorities of the delegates for different categories. And for some categories she may want to not delegate to any of them if two or more of her chosen delegates votes in different directions.
ALL of these functions can be described as the choise to delegate to choosen alghoritms. That means that you can have a system there you only can delegate to ONE delegate. But this delegate may be a computer program that makes the choise based on a whole lot of other delegates and systems of categorisation.
The voting system can function a bit like the Firefox web browser. There should be a clean and easy interface that will cover at least 95% of the users. This interface may have advanced functions that can be unlocked for those who desire. But everyone should also have the option to install plugins that suit their needs for navigating the democracy system (intellisphere). Popular plugins should be integrated in the core. That is a way to make the democracy system in itself democratic. There should never be one group of people that decide what the best way for reaching decisions is for you.
One simple step, with this vision in mind, is to give the ability to rank delegates and to assign different delegates for different categories.
But the DEFAULT behaviour would be to give all chosen delegates the same priority. If two or more delegates votes on the same thing, in opposite directions, the default will be to NOT delegate to any of them and to NOTIFY the person of the deadlock. The person would be encouraged to examine the issue, look at the arguments, and make a decision. That would counter-act most "populistic" votings, since you would expect that at least one of the chosen delegates has a deeper understanding of the issues.