Some great answers arose around the first amendment, stating that perhaps the "establishment clause" should have stayed in Madison's original form, stating that congress shall "establish no National Religion", i.e. the "Church of America" similar to the Church of England, where the King is the head of the church. Of course congress being what it was, they bungled it up and created the current establishment clause: "Congress shall make no law respecting an establishment of religion" which has been wrongly interpreted to mean that no local/state/federal governments can acknowledge the existence of God. This was a great one.
Another caller suggested the inclusion of term limits on all federal politicians, including Supreme Court Judges. He suggested 8 years, max - two terms of 4 years being elected by the people. I would modify that and say one term of 10 years appointed by the President and approved by Congress to a class... The seats should be "numbered" and the appointment to one class should not disallow appointment to another seat by a different president and congress. There should be a three class rotation, just like the Congress - meaning that a justice could serve no more than 30 total years... Of course the intent of the lifetime appointment was to raise the justices above the political fray - but little good that did... so if they too should be politicised, let us set it to a review!
If I had to nail down some changes, mine would be simple:
1. National Debt, expanding definition of Article VI
2. 10th amendment and secession
Regarding national debt. Article VI addressed the continuation of validity of debts held under the Articles of Confederation. However, Washington's farewell address explicitly covered the negative effects of continual debt and the burden of taxation to that end... and as such, the Constitution should include a balanced budget amendment and a national debt clause in addition to the statements made in Article I section 9:
No Money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law; and a regular Statement and Account of the Receipts and Expenditures of all public Money shall be published from time to time.
It should read something like:
"Debts incurred by the Congress of the United States shall have terms not exceeding ten years, and shall not be termed in any way so as to entangle the United States in foreign alliances nor dependency. The budget of the Congress shall remain balanced, reducing the burden of taxation necessary to the continued peace and prosperity of these United States.
I believe that such a clause would eliminate foreign debts, keeping the monetary burden of the United States on the people of the US - making such outrageous socialist policies directly felt by the people, and ensure a small and purposeful government - to maintain peace and prosperity.
Regarding the 10th and secession. There are very specific rules by which the states have to live, stated in Article I section 10:
"Section 10 - Powers prohibited of StatesThe tenth amendment further instructs "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."
No State shall enter into any Treaty, Alliance, or Confederation; grant Letters of Marque and Reprisal; coin Money; emit Bills of Credit; make any Thing but gold and silver Coin a Tender in Payment of Debts; pass any Bill of Attainder, ex post facto Law, or Law impairing the Obligation of Contracts, or grant any Title of Nobility.
No State shall, without the Consent of the Congress, lay any Imposts or Duties on Imports or Exports, except what may be absolutely necessary for executing it's inspection Laws: and the net Produce of all Duties and Imposts, laid by any State on Imports or Exports, shall be for the Use of the Treasury of the United States; and all such Laws shall be subject to the Revision and Control of the Congress.
No State shall, without the Consent of Congress, lay any duty of Tonnage, keep Troops, or Ships of War in time of Peace, enter into any Agreement or Compact with another State, or with a foreign Power, or engage in War, unless actually invaded, or in such imminent Danger as will not admit of delay."
By these two clauses, so long as a state remains in the Union, they must abide by these rules - but the tenth gives them the right to break from the Union, as they are not prohibited by Article I section 10.
I would make this more clear by specifically granting the right of secession should a state no longer deem the rules governing the Union just, at which time they are returned their full sovereign and independence from the Union without consequence of invasion so long as they remain on peaceful terms with the remaining states of the Union.
What good is a perpetual Union if the states lose their sovereign and their ability to challenge the central government? It is no longer a union of sovereign states, rather a single nation of one government rule - tyrannical in nature - eliminating the fundamental right of Liberty outlined in the Declaration of Independence. Any state and people so inclined to remove themselves from the Union should, in a free society, be allowed to do so. It strengthens a Union if ultimate power is truly retained by the people and the states, as is the intent of the tenth.
The constitution is nearly flawless... it is the corrupt nature of men that have perverted the document or downright ignored it in order to attain power and status or to slowly enslave the people of this nation under the master of an uncontrolled central government... the very things the anti-federalists warned of.
These are my suggestions.
What are yours?