Los Angeles — The watchword now becomes ''unity'' for election-weary Democrats seeking to oust Ronald Reagan from the White House. Walter Mondale - with the Democratic nomination now apparently in his grasp - moved quickly on Wednesday to heal the party's wounds. Even before all the votes were counted, Mondale campaign manager Robert Beckel said:
''We are ready to talk to any and all Democrats who want to join and unify the party.''
In the near future, Mr. Mondale or his aides may directly approach both Gary Hart and the Rev. Jesse Jackson to begin the process of bringing the party back together after a grueling campaign, Mr. Beckel said.
Mondale's strong victories in New Jersey and West Virginia this week, combined with a sizable bloc of votes from California, finally gave him enough delegates to lay claim to his party's nomination.
Democratic voters once again, however, showed signs of ambivalence on the final day of voting, just as they have since the first primary in New Hampshire more than three months ago.
Mondale badly needed a hearty three cheers from Democratic voters. Instead they gave him only two, and saved the loudest cheer of all, the California primary, for Gary Hart, the young Colorado senator who would not quit.
Mr. Hart, who captured South Dakota, New Mexico, and a majority of the California delegates on the final voting day, vowed: ''Our work has just begun.''
Despite those brave words, Mondale's nomination seems assured. Top Mondale aides, however, are concerned that Hart's ability to ''make mischief,'' as they put it, could be substantial in the coming weeks.
Hart aides indicated that he would immediately begin a personal effort to court Mondale delegates. The senator will use his California victory to argue that he, not Mondale, is the candidate with the broader appeal.
Hart also has other options. He could challenge the credentials of Mondale delegates from some large Northern states. He could continue to press claims that Mondale may have received illegal financial help from political-action committees. He could also form an alliance with the Rev. Mr. Jackson in hopes of inserting some controversial planks in the Democratic platform.
Nor should Jackson delegates, nearly 10 percent of the total, be forgotten. Jackson ran last in all five of Tuesday's primaries. But his constituency, mostly black voters, will be desperately needed by Mondale in a showdown with President Reagan. Without kind words from Jackson, black voters could stay away from the polls by the millions, and dash whatever prospects Mondale may have for victory in November.
Mondale aide Beckel discounted the seriousness of the Mondale-Hart and Mondale-Jackson squabbles.
''If you look back at Democratic conventions - 1972, 1968 - when there really was division in the party over the war in Vietnam . . . this really doesn't compare to that. . . .
''I don't see any reason at all why the party can't get together, why Mondale , Jackson, and Hart can't reconcile their differences. It's not quite as divisive as it seems on the surface.''
Jackson's specific demands on Mondale could be hard to meet - at least in full. There are essentially two of them.
First, Jackson received a higher percentage of votes than delegates during the primaries. As he put it on Wednesday morning:
''I cannot sit idly by and allow 15 percent of the vote (for Jackson) in Vermont and no delegates, 15 percent in Arizona and no delegates. Whole numbers of people (who) voted for me are disenfranchised.''
The party's rules on voting and the apportionment of delegates need changing, Jackson says, and he intends to make that fight. That demand might be met by Mondale, at least partly. There is already a move to award Jackson at least a few more delegates. But Jackson is also insisting upon an end to runoff primaries in the South. These rules, he claims, are unfair to blacks.
Mondale will tread lightly in this area. Southern political leaders, such as Georgia party chairman Bert Lance, are adamantly opposed to doing away with runoffs. ''If it ain't broke, don't fix it,'' Mr. Lance says with a smile. Southern Democrats argue that doing away with second primaries would turn Dixie over to the GOP. Besides that, they argue that runoffs are democratically sound, a bow to majority rule. How can that be unfair?
As a practical matter, Mondale is as concerned about holding onto Southern white votes as Southern black votes. He needs both, and can afford to offend neither group.
Meanwhile, for a few precious moments, Mondale now can bask in his first-place finish in the race for delegates. Unless something totally unexpected happens, he should easily have the delegates needed for the nomination.
On Wednesday, unofficial tallies by various news agencies and networks were all showing Mondale at or near the magic number of 1,967. The Associated Press gave him 1,959, UPI made it 1,967, CBS said 1,956, ABC was at 1,975, and NBC at 1,994.
More than 200 other delegates are still uncommitted. Even if he is still a few votes shy, it should be easy for Mondale to pick up the few extra delegates he needs between now and the July convention. In fact, on Wednesday Mondale claimed he had done just that.
If there is any element of disappointment in the Mondale camp today, it is due to California. California is where Democrats will hold their national convention. It is a symbol of the growing power of the West. One out of every 10 Americans lives here. Its economy has grown to $350 billion - so large that if California were a separate nation, it would have the seventh-largest economy in the world.
Yet California and the West are areas where Democrats seem to grow weaker and weaker politically, especially in presidential contests. The most apparent reason: prosperity has made Westerners economically conservative.
Into this state strode Mondale, symbol of old-style Democratic coalition politics. Big labor supports him, as do traditional big-government advocates: the poor, the elderly, the minorities.
For Californians, Mondale was no match for Hart. NBC exit polls showed Hart sweeping the state among the same groups to which he has appealed in earlier races. Hart easily carried those with college degrees, the young, those making more than $20,000 a year, professionals, white-collar workers, nonunion voters, and independents.
Hart's aides argue that Mondale is so weak in the West that his nomination will automatically concede everything west of the Mississippi River to Ronald Reagan.
Mondale aides know there is some truth to that argument. ABC exit polls in California found that if Mondale were the Democratic nominee, he would get little help from all those Hart voters. The survey found that 37 percent of Hart's voters would support Mondale, but 35 percent would switch to President Reagan, and 29 percent say they would just stay at home.