Although the nominees have long since seemed certain, how the presidential primary endgame plays out June 3 will still bear significance -- for both the 1980 and 1984 elections.
With the Ohio primary, President Carter's and Ronald Reagan's strengths will have been weighed in the southern reaches of the big Midwestern states. And California, climaxing the westward march of the campaign, could either curb or encourage Sen. Edward M. Kennedy's White House aspirations for 1984.
California already decides more than 9 percent of Democratic convention delegates and in 1984, after reapportionment, will determine a whopping 12 percent. A California rejection of Mr. Kennedy would invite other Democrats into the field and weaken the Massachusetts senator's claim as leader of his party's liberal wing.
Of the eight states with primaries June 3, President Carter has chosen to finish the contest in Ohio, a state he carried by barely 11,100 votes over Gerald Ford in 1976.
Ohio offers the President his best chance in Tuesday's "big three" contests -- the third state is New Jersey -- to defeat Senator Kennedy decisively.
Mr. Carter wants to close with at least one more win in the chain of states that begins with Illinois (which he won in March) on the west and continues eastward through Indiana (which he also won in May) along the "industrial crescent" to the Atlantic. Defeat possibly awaits him again at the coast, where New Jersey offers Mr. Kennedy his best chance Tuesday. Already Senator Kennedy has beaten him in Pennsylvania and New York.
With a similar eye to November, Ronald Reagan also has campaigned heavily in Ohio. The crucial part of the Ohio contest could occur not in the northern and central cities, but in the conservative southern and rural reaches, where Mr. Carter beat Gerald Ford, where Mr. Kennedy is not a factor, but where Mr. Reagan could prove formidable. Heavy joblessness from the current recession would weaken Mr. Carter for November in the cities of Ohio and other industrial crescent states.
In the West, Carter supporters faced a hard choice for their final-day strategy. Some felt Mr. Carter's failure to campaign hard for California's 1976 primary cost him the state that fall. The Carter campaign staff has said that, with the tight federal spending lid, the cost of a presidential primary visit to California -- even though it would be under $40,000 -- has kept him away.
But the Carter campaign spent that much for a successful, last-minute Oregon primary media blitz two weeks ago. It is reportedly spending 15 times that much in Ohio.
West Coast observers think Mr. Carter is already conceding California to Mr. Reagan for November -- or that he wants to diminish a possible Kennedy win by making California a noncontest.
A win for Mr. Kennedy in California would be necessary to sustain any effective convention challenge to President Carter, the senator's campaign staff concedes. California is regarded by most observers as a state a Kennedy should carry big.
But the impact of a loss for the senator there would carry beyond the Aug. 11 -14 convention in New York to his 1984 prospects.
A recent California poll found the drag of the senator's past was costing him 15 percentage points with the Democratic electorate. Without Chappaquiddick -- an event 29 percent of the state's Democrats thought pertinent to their voting -- Mr. Kennedy would have been leading Mr. Carter by 10 points instead of trailing by 5 points. By comparison, Mr. Reagan lost only 5 points to his Republican rivals due to "the age factor."
Vice-President Walter Mondale, a potential 1984 contender, already is doing as well as Senator Kennedy in trial heats against Ronald Reagan. Mr. Mondale has carried the burden of the 1980 White House re-election effort, and many Democrats feel he has worn well as a campaigner for two presidential seasons now. He has White House experience and his years as a protege of Hubert Humphrey still link him with the Democratic liberal wing Senator Kennedy now claims to champion.
Mr. Kennedy's people have resolutely shied away from talk of 1984. But privately they anticipate a Mondale rivalry then. And they concede a California loss for the senator would spur other Democratic rivals -- perhaps Gov. John D. (Jay) Rockefeller IV of West Virginia or Sen. Daniel P. Moynihan of New York -- to the challenge.
The remaining states holding primaries June 3 are Montana, New Mexico, Rhode Island, South Dakota, and West Virginia. In all, 21 percent of both parties' convention delegates will be chosen on that day.
This is by far the biggest tally of the primary season -- double the 10.1 percent totals for the Southern primaries March 11 and the Connecticut-New York primaries March 25.