New Orleans — The Democrats are shopping for a moderate alternative to President Reagan for 1984.
Many party leaders say they hope Sen. John Glenn of Ohio - a former astronaut with potentially strong appeal in the crucial Midwest and South - can live up to his prospects and show the kind of personal warmth and partisan fire needed for a White House campaign.
The consensus of Democratic state chairmen, meeting here for the party's showcase of its 1984 talent, was that Senator Glenn helped himself more than the other White House would-be's - former Gov. Reuben Askew of Florida, Sen. Alan Cranston of California, Sen. Gary Hart of Colorado, and Sen. Ernest Hollings of South Carolina. Glenn was relaxed and showed he could poke fun and wax serious - unlike his earlier, wooden performances. But whether it was enough to move Glenn from the second tier of contenders into an orbit near those of the more liberal front-runners, former Vice-President Walter Mondale and Sen. Edward M. Kennedy of Massachusetts, remains to be seen.
The Democratic quest for 1984 is dominated by these themes:
* If the economy is showing mixed signs in the fall of '83 - considered the most likely outcome - Mr. Reagan would still be in a strong position to run again, Democrats say. Campaigning against Reaganomics might not be enough. A more positively viewed candidate like Glenn - or another fresh presidential face like Senators Hart or Cranston - could possibly best compete.
* If the recession hasn't abated by then, a more liberal Democrat, one associated with the party's past battles and traditions, could rush to the fore. Pollster Patrick Caddell points out that even in this month's election, two radical Republican candidates for governor - Lewis Lehrman in New York and Richard Headlee in Michigan - ran remarkably strong campaigns. The public could be ready in 1984 for another sharp liberal-conservative White House battle to help clear the air.
* In hindsight, both the 1982 and 1980 campaigns now look like more pragmatic elections than ever. The public's basic political attitudes and allegiances have not shifted in any lasting manner. Burns Roper, president of the Roper Organization, points out that the public's split this fall among Republicans (25 percent), independents (28 percent), and Democrats (47 percent) varied only within two points of October 1980 and January 1974.
Similarly, by political philosophy the last election cycle showed no great swing. In September 1982, the numbers calling themselves conservative (45 percent), midroad (33 percent), and liberal (19 percent) were within four points of their 1980 and 1974 proportions.
Pollsters say this lack of change indicates that the battle for the hearts and minds of the public remains to be won. Democrats say they realize they need a set of choices - even as late as convention time - so they can adapt to economic circumstances as the election approaches.
* The Democratic nomination may not be wrapped up until convention time because of changes in the process since 1980, whatever the course of the economy. ''I see the possibility of a 'brokered' convention,'' says Darrell Beers, vice-chairman of the Washington state Democratic Party, ''especially if Kennedy and Mondale kill each other off in the early going. Nobody's going to go in and sweep it on the first ballot.''
This is partly for technical reasons. The Democrats will send at least 560 unpledged or uncommitted delegates to their convention, and the ''binding rule'' has been eased.
Many Democrats may hold their options open to the last moment. ''I won't come out for anyone until the convention,'' says Pat Lea, Missouri Democratic chairman. ''My delegation will be split. I'll favor a moderate-conservative candidate. It'll depend on the economy. We might switch to a liberal if the economy's down in the dumps. Then it could be Kennedy or Mondale.''
Democratic leaders in some states, particularly in the South - which gets a bumper crop of delegates at the next convention after reapportionment, and as a bonus for strong recent Democratic showings in the region - are leery of a Kennedy or Mondale nomination.
''Mondale is a finished issue in this state,'' says Daniel Becnel, a Louisiana lawyer and Democratic fund-raiser. ''Right now everybody in this state is with Kennedy or Reagan. But Kennedy can't win - and that's remarkable in a state where 93 percent of the populace is Democratic. Glenn's the only viable middle-of-the-road candidate. Nobody else can raise enough funds. It's Reagan, Kennedy, Mondale, and Glenn.''
However, ''even in a Glenn-Reagan race, it would still be Reagan,'' Mr. Becnel says. ''We don't really know what Glenn can do yet.''
The relatively strong Democratic success this month should not mislead Democrats into false confidence about 1984, party strategists say.
''At the congressional and lower office levels, the public is still firmly Democratic - not rock solid, but firmly,'' says Democratic pollster Paul Maslin. ''But Democrats have to earn back trust on a national level. That's what we have to do by '84. And that will be very difficult to do.''
* The public in this next political cycle is still open to a positive appeal, despite the negativism of this fall's campaign. This prospect helps fire the hopes of Democrats like Hart, Cranston, Askew, and Hollings, not just Glenn.
''Ronald Reagan has polarized the public and set up a sense of class differential,'' says Peter D. Hart, a Democratic strategist. ''Voters continue to be in a transitional period. There is a real market for a positive political vision. Voters are looking for some constructive help.''