Our government is an absolute mess. It's dying. It has reached the point where insanity is commonplace. Can it be fixed? I'm inclined to think not. Just as bailouts can't save the banks (their obligations exceed the value of everything in the world, which they don't quite own yet), anything we do now is too little, too late. However, we should learn from the mistakes that brought us here. What were the mistakes, and what changes could have prevented them?
The source of most mistakes is Congress - the House of Representatives and the Senate. The biggest mistake Congress makes is borrowing money. Congress can't control spending because there is no limit to the amount it can borrow. So a new rule is needed in the next Constitution - government may not borrow money or incur any debt. I can't think of a better or more simple rule to limit government size and power. It also weakens the control the central bankers have over our government.
Legislation currently passes in Congress by a simple majority - let's change that to a 75% majority. The higher the percentage, the harder it is to pass controversial bills and engage in party politics. And the less Congress will get done (that's a good thing). Complex bills that are too long to read must be prohibited. Let's keep it simple by limiting legislative bills to a single subject and a single page (500 words or less). And one more important fix - disallow legislation that benefits special interest groups. Bye-bye lobbyists and "pork".
As for the executive branch, we should strip the President of the power to pardon - this just encourages the executive branch to hire people to commit crimes for them. In fact, let's just get rid of the president and vice-president. They serve no real purpose and are simply holdovers from the days of royalty. We'll save a huge amount of money by eliminating presidential elections. Congress can handle the duties performed by these two talking heads, and in one fell swoop, we eliminate the two biggest liars in government.
Finally, the judicial branch. Our laws are impossibly complex and too numerous. This has to be changed, but how? My head hurts, so I'll leave this one as an exercise for the reader. In other words, help!