PRESIDENT BUSH'S plans to back a constitutional amendment limiting time of service in Congress may generate fresh life for an old idea that hasn't improved much with age.
Combined with an anti-incumbent mood that showed in the last election, presidential support could push term limit proposals a long way.
The idea isn't a good one, but it's not hard to understand its popularity with Americans resentful over the monotonous re-election of legislators who repeatedly fail to resolve the same old problems.
It is true, of course, that the 22nd Amendment to the Constitution, ratified in 1951, limits presidents to two terms. So why not extend the idea to Congress?
But the analogy quickly crumbles. Presidents are elected nationwide; members of Congress, by states or smaller districts. The president, a single individual, could become a dictator if unchecked, and a limit to two full terms helps prevent that. The 535 members of Congress are naturally divided.
A limit on congressional terms -- the White House has not given any details of the proposal -- would not just curb the time marginal or inadequate representatives could serve, but would end the careers of outstanding ones as well.
It would deny the nation the seasoned service of representatives who had taken the time to become expert in specific fields. When the representative or senator was gone -- bounced automatically by law, gone too would be his or her knowledge of hous ing or military strategy.
More than ever, deep knowledge of the issues would be left to the unelected, unaccountable congressional staff.
But the clinching consideration is really that term limits crimp the democratic franchise of the voters. They say to voters: No matter how much you like or respect a senator or member of the House, you may not -- repeat not -- return that person to office more than three or four terms.
Better ways exist to rid Congress of dead wood.
In the present anti-incumbent public mood, political organizers and would-be candidates should see an opportunity. Ambitious challengers for House and Senate seats -- so often scared off in the past by the seeming invulnerability of incumbents -- should even now be gearing up for the 1992 election.
Let them decide, organize, start to raise funds and get out around their districts, meeting the people whose support they seek.
Congress and the states need to reform the election law to make campaigns a more level playing field financially. And they need, especially in New York, to liberalize enrollment and voting procedures.
At first glance, a limit on congressional terms may look alluring. But voters can now throw out an incumbent any time a majority agrees.
The more thoroughly citizens examine the idea of artificial terms, the more they will discern drawbacks that can undermine democracy.