I am not sure I would really want to do this, but I often think that I would like to change our governmental structure to make it impossible to have divided government. Divided government is the situation we have now where Congress (or just one house of Congress) is controlled by the party that does not have the presidency.
When we have divided government, it seems like nothing gets done even if there is, as there is now, a sense of crisis in the country. The Democrats and Republicans can't agree on anything and our problems grow as they bicker. It would be nice to see us have a system in which one party got to try its plans out without being hindered by the other party. Then we could actually see which party had ideas that would work.
I would change things, then, so we would have fewer checks and balances and the executive and legislative would be controlled by the same party.