That'd be a really bad idea in my opinion, because it doesn't mean that Washington will have to stop spending, it only means that if they spend more they have to tax more, and they can dodge responsibility for it because it's required by the Constitution.
A better idea would be some kind of cap on spending as a percentage of GDP, but I don't know that I would put it in the form of a Constitutional amendment. What would help is just having elected representatives who will do the job they were hired for.
