Give us another five years and we'll be celebrating the bicentennial of the US Constitution, one of the most remarkable documents in history. I was in the British House of Commons the other day noticing all the strands of wire dropping down like fishlines from the venerable ceiling picking up the voices, I suppose, of the speakers below. It's different in the US Senate. There a member when he speaks lifts his amplifier and pins it to his chest or tucks it into his coat pocket. Then he, too, is wired for sound. In spite of the wires, none of the honorable members has yet strangled himself. The amplification, I may add, is splendid.
Both these legislative bodies evolved from the same beginning. It may sound heretical to say it but I wish the Founding Fathers in that humid summer in Philadelphia in 1787 could have paused a little while. The British hadn't invented their own cabinet system yet. Let me say, speaking as a selfish journalist, the show they put on in Westminster is vastly more dramatic than the one in Washington. I defy the most languid to look down from the gallery at ''Question Time'' in the Commons, with Prime Minister Margaret Thatcher and her government on one side of the aisle and the opposition parties on the other side , throwing questions and replies and well-bred taunts at each other, without being thrilled. It's the best matinee performance in London.
What would this system be like in Washington? Instead of the press asking questions of President Reagan, he and his teammates would be down on one side of the aisle in Congress attempting to explain the most dramatic public questions of the day, while the duly elected leaders of the opposition would be raising interrogations and trying to indicate how much better they could manage affairs.
You say America couldn't stand the excitement? It's just what the United States with its languid electoral turnout needs. I believe that every big democracy in the world has some variety of this parliamentary system save the US. America is the outsider, not the rest of the world.
That doesn't mean that their system is necessarily better than ours (I think it's doubtful if any other country could manage our system, just as I doubt whether Americans could ever play cricket). But the show in Washington often drags. As a reporter I often ask, who's in charge? Is it Congress, the White House, the courts, the bureaucracy, or some little pipsqueak regulatory agency that got its power under Franklin Roosevelt and can't be curbed short of the Supreme Court?
In Philadelphia last May, Chief Justice Warren Burger was extolling the 1787 Constitutional Convention and noted the ''great fear of central governments'' that permeated it, ''stemming from the fact that the revolution had been fought to escape from the clutches of a distant and strong central government in London.'' It solved the problem, of course, by inventing the ingenious system of checks and balances. That's fine, but who's in charge?
A little after Mr. Burger spoke, Lord Chancellor Hailsham in London was introducing President Reagan to the Houses of Parliament in the Royal Gallery. ''When our paths diverged 200 years ago,'' he said, ''the United States reverted to the earlier 17th-century model of an executive head of government, independent of the legislature as well as of the judiciary.''
In short, by this interpretation, the president became a kind of king. England already had a king and royal family but went ahead with its parliamentary system on the side. Or, as his lordship put it, ''We and other nations . . . pursued the system, already recognizable at the time of the Declaration of Independence, of an executive drawn from the legislature but independent of the head of state.''
Well, I'm not sure the lord chancellor has his timetable quite right: The English cabinet system evolved over a period of years (stimulated and encouraged by the American success in running a government without any king at all).
We can argue the chronology of the thing and which is the better system. But for drama, give me Westminster.
It is true we had a lot drama in Washington last week in the final hours of the budget fight with cameras flashing back and forth between White House and Congress. Such clashes come rarely. But suppose Mr. Reagan and his team had conducted their fight in the front rows of Congress, face to face with opponents. That would have been more spectacular.
One more thought. The US budget has been under debate now for almost a year: Commercial interests haven't been able to lay their tax plans with certainty. In the normal parliamentry usage this couldn't have happened: The government brings in its budget at the start of the year; if the opposition can upset it, fine; there is an election to decide who's in charge, and the budget gets written in any case. Washington gets its budget, too, after a while. We finally have ours, and we hope it works. It's taken a long time.