THE LATE ALAN BARON, the roly-poly political analyst and Washington raconteur who edified and amused the nation's political cognoscenti for two decades before his death in 1993, used to watch the slow atrophy of the national party conventions with sadness and pain. And he concluded there was only one solution -- a reform so simple and so effective that it probably never would be adopted: the two-thirds rule.

If the parties could muster the boldness and confidence to require a two- thirds majority for their presidential nominations, the current slow death of the party conventions would he reversed. And soon the conventions would be restored to their former robustness, verve, and excitement.

It was never clear to what extent Baron's tongue was in his cheek when he advocated the two-thirds rule. But he clearly harbored no doubts that it would restore and save the conventions.

Of course, the idea would generate considerable opposition. Some would consider it decidedly undemocratic. After all, the Democrats' old two-thirds rule, tossed aside in 1936, was instituted to give the antiblack South a veto over any candidate who wasn't sufficiently segregationist. And many would wonder whether we really want to give so much power to minority interests within the parties, such as the religious Right.

But Alan Baron understood something that today should be obvious to all: However flawed the Democrats' old two-thirds rule was, its ills didn't come close to the ills of the current system.

The party conventions have been rotting in quadrennial steps for years. First, the decision-making role of the conventions was obliterated. That sapped the suspense and excitement that once riveted the nation at convention time. That led convention planners to tailor their proceedings to the eye of network television, which led network executives to abandon the proceedings in disgust. That in turn led to desperate efforts by party functionaries to bring back the cameras with the kind of fare that draws big audiences for Entertainment Tonight.

So in place of raucous politics with actual meaning we get, at the Democrats' confab, the Macarena, Christopher Reeve in a touching but politically irrelevant talk, and persistent heartstring tugs with stories of human drama that have little political meaning. Or, at the Republicans' event, a program so scripted and sanitized it could pass for a high school assembly. Watching these things is like eating a mayonnaise sandwich on Wonder Bread.

The result is that, in coming campaign years, the conventions will be scaled back, then finally put to sleep entirely.

But that will be bad for the parties -- and very bad for American democracy. Without their conventions, without a quadrennial gathering to explore and deal with party crosscurrents, fault lines, conflicting impulses, and elements of unity, the parties themselves will continue to atrophy, until they finally lose all reason for being.

Now consider what would happen if we had the two-thirds rule. First, the dynamics of the primary season would change utterly. In the current system, the political psychology leads to the frontrunner's being anointed early, as the money and political support for also-rans dry up. But, if the frontrunner had a steeper, longer hill to climb to nomination, competitors could hold their support longer, and their cash spigots would stay open longer.

After all, if the frontrunner could be denied a first-ballot victory, anything could happen in subsequent ballots. And anyone with a cache of convention delegates could wield big influence in the final nominating decision.

What's more, a return to convention-brokering would give states a big incentive to return to the old days of choosing convention delegates through caucuses and state conventions. Party pros would want to amass and husband convention clout, and the way to do that would be to abandon primaries.

Perhaps we would see a return to the "favorite son" ploy, in which big states send their delegates to conventions committed to the state's top party bigwig, all the better to play an influential role in the convention deal- cutting that would emerge in any multi-ballot convention.

All this in turn would have a large impact -- and a healthy one -- on the nominating process. With fewer primaries -- designed essentially to prove vote-getting strength it wouldn't take so much money to run for the nomination.

The presumed $ 20 million entry fee (in today's dollars) would be scaled back to the point where the field of potential candidates could be expanded. The fund-raising game, now such an integral part of the process, wouldn't winnow possible candidates so brutally before the race even gets started.

The two biggest objections to this simple reform are that it is antidemocratic to require a supermajority and that it would give too much power to minority interests.

But what is so antidemocratic about giving particular interests enough clout in convention deliberations to reflect their numbers on the convention floor? If African Americans in the Democratic party or the religious Right in the Republican party can amass 25 percent of the delegates, why shouldn't they be able to leverage the political power represented by those numbers?

They wouldn't be able to dictate the nominee, after all. They might have a veto power in the early negotiations, but eventually they would have to compromise on the final decisions, as would every other state delegation, presidential candidate with delegate strength, and interest-group contingent.

And think what this would do for conventions -- and the parties. There would be a high likelihood of political intrigue at the quadrennial party gatherings, which would generate suspense, which would in turn generate political interest across the land. Instead of complaining about a lack of stories, reporters would be out and about trying to explain to their readers and viewers the complexities and likely outcomes of this intriguing new system.

And the intrigue and suspense would generate real debates, efforts by speakers at the podium to send waves of political sentiment across the hall. Today's fluff would be replaced by tomorrow's raucous discourse and real political substance.

Who knows? It might even diminish the growing political cynicism that is eating away at the body politic like acid. I think the parties should give this a try. They can call it the Baron Rule.

Robert W. Merry, executive editor of Congressional Quarterly, is the author of Taking On the World: Joseph and Stewart Alsop -- Guardians of the American Century (Viking).

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