Democratic nod is Mondale's -- if he doesn't stumble

If you want to know how the 1984 race for the White House is going, you might check the lines in front of your local movie house this fall. That's when ''The Right Stuff'' will flash onto 1,600 theater screens in the United States, and as one insider notes: ''It makes John Glenn look like the all-American boy.''

''The Right Stuff'' is Hollywood's latest $30 million blockbuster, a three-hour adventure based on Tom Wolfe's best-selling book about the first American astronauts. It will be released Oct. 21 and should peak in November and December, just a couple of months before the first presidential primaries.

All this is good news in the Glenn camp, which has watched its man trail in the polls and in fund raising behind front-runner Walter Mondale through the spring and summer.

But the current political wisdom here in the capital is that despite the Hollywood publicity for Ohio's Senator Glenn, former Vice-President Mondale remains the man to beat. Here's how the six Democratic candidates are currently seen here:

Walter F. Mondale. He is on top in the polls (41 percent of Democratic voters prefer him as the nominee), and in fund raising. Mr. Mondale also has the best-organized team. Endorsement by the AFL-CIO this fall would be an important boost because it would help Mondale get out the vote in the primaries, where the turnout is usually low.

John Glenn. Second in the polls (25 percent), Glenn has raised only about half as much money as Mondale. Money could be critical in next year's primaries, which come close together and leave little time for raising funds in between primaries the way Jimmy Carter did back in 1976.

Alan Cranston. Far behind (7 percent), California Senator Cranston also sank capitalizing on the nuclear freeze issue and winning support from many Democratic activists.

Gary Hart. Also low in the polls (4 percent), Colorado Senator Hart's campaign suffered from Cranston's successes, as they were working the same liberal political lode. Hart must make a greater appeal to political moderates if he is to escape Cranston's shadow, insiders suggest.

Ernest F. Hollings. At the bottom of the polls (2 percent), South Carolina Senator Hollings concedes he has failed to get the public's attention. He's now counting on a good showing in the Maine straw poll Oct. 1 to put his face on Page 1 around the country and fire up his campaign.

Reubin Askew. Also standing on the bottom rung of the polls (2 percent), the former Florida governor hopes to pull off some quick, early surprises in Iowa and New Hampshire next year. His campaign is in excellent financial shape, and his small political team has been building an organization in key, early states.

In all of this, there are really no political surprises, no unexpected turns from what the experts predicted months ago.

The political cliche here is that the '84 nomination remains Mondale's to lose, not the others' to win. If Mondale stumbles, if his political team makes a series of major gaffes, then Glenn or one of the others could climb to the top. Otherwise, Mondale should take it rather easily.

Beyond these cliches, however, the picture is more complex, the outcome much less certain.

No one here forgets that in the '76 election, Hubert H. Humphrey was well on top in the polls about this time, while an unknown former Georgia governor, Jimmy Carter, was at less than 1 percent. Eight months later, Mr. Carter had won.

Then there is the McGovern factor. Former South Dakota Sen. George McGovern, the Democratic presidential nominee in 1972, says he may very well get into the race. Even a marginal showing by the liberal McGovern could cut into Mondale's strength, and help Glenn.

Mondale could also be hurt if the Rev. Jesse L. Jackson, the civil rights leader, adds his name to the contest later this month. Again, like McGovern, Mr. Jackson would drain away liberal support that would normally gravitate toward Mondale, and indirectly boost Glenn's prospects. Jackson's entry into the race could be especially important in the South, where large numbers of blacks are expected to vote for Mondale, and offset heavy white support there for the more moderate Glenn.

Finally, there are the voters, who have so far only been heard from through the polls.

''Up until now, the voters haven't really been paying attention,'' says a Glenn political adviser. ''But that will change in the coming weeks. Interest is growing. Voters will start to listen, to weigh what Glenn, Mondale, and others are saying. And that will start to impact on the polls. Then you'll see this race get more exciting.''