Yes, the U.S. Constitution should have a balanced budget amendment, because the country cannot live with a deficit forever. Eventually, the country will have to repay that debt, which will result in large austerity cuts, like those seen in Greece. This will result in massive protests from government workers, who will not want to lose their plush jobs.
All governments should be required to maintain a balanced budget. Individuals are required to live within their means. If they do not, they pay the consequences. Government, whether state, county, or federal, should be required to do the same. It is not right for them to spend whatever they want and leave the future generations to pay the price.