Atlanta — Throughout Southern history, blacks have been a focal point of most political struggles, and they are once again as the 1984 presidential race heats up. And once again, the Southern strategy of the Republican Party is based on a realistic appraisal that at least for now, most blacks vote Democratic.
(The percentage of Southerners who are Republicans has not increased and may have decreased during the Reagan years, according New York Times/CBS News polls taken in January 1980 and January '84. The recent poll found the GOP at 19 percent, the Democrats, 48 percent.)
So with a major Democratic voter registration drive under way, aimed particularly at blacks, Republicans are beginning their own drive to sign up voters - primarily whites sympathetic to the Republican Party.
''We will not offset the massive Democratic registration in the black community,'' says US Rep. Carroll A. Campbell Jr. (R) of South Carolina, who is active in the Reagan-Bush reelection campaign. But, he says, by carefully targeting potential Republican voters in GOP pockets across the South, the party hopes to increase its strength.
President Reagan's margin of victory - he won every Deep South state except Georgia - was quite narrow in several of those states.
Another key element of the Southern strategy, according to remarks by various administration officials at a recent conference here of Southern GOP leaders, is not much different from the national Reagan-Bush strategy: convince voters that they are economically better off today than they were three years ago.
US Labor Secretary Raymond J. Donovan says he thinks another Reagan campaign theme - stressing ''family and respect for the flag'' - will be especially well received in the South.
But as a minority party in the South, despite several Republican sweeps at the presidential level, Republicans are pinning much of their hopes on their efforts to attract more voters.
There was a time - from Reconstruction to the days of Franklin D. Roosevelt - when blacks, to the extent they were politically active, were Republicans, notes V.O. Key Jr. in his classic book ''Southern Politics.'' Then gradually whites wrested away control of the party. And the Roosevelt policies attracted blacks to the Democratic Party, where most of them eventually wound up - and have stayed.
But Representative Campbell sees a dilemma developing for the Democrats that involves blacks: If the Rev. Jesse Jackson manages to wind up second in the Democratic nomination race, even though far behind Walter Mondale, what will Mr. Mondale do? If Mondale does not pick Mr. Jackson as his running mate, will black voters be offended? Might some be so offended they would vote Republican? Campbell hopes so.
In the long run, he says, ''the hope for the Republican Party in the South is a growing black middle class.''
Some politically active blacks in Atlanta say their concern is that some black voters, especially young blacks, attracted to the polls by Jackson's candidacy in the primaries may be too disillusioned to return on election day in November if Jackson is not on the ticket. Most Republicans interviewed at the conference on Saturday were optimistic about a Reagan victory in the South but were less optimistic about races for lower offices. And Georgia Republican chairman Bob Bell said flatly there is a ''good possibility'' that President Reagan will not carry the South.
In remarks prepared for the conference here, Republican Sen. Mack Mattingly of Georgia told party leaders the party had ''made a mistake.
''After we won in 1980, we stopped thinking,'' he said. After accomplishing many party goals by 1982, ''we unknowingly became complacent. . . .'' He urged a longer-range agenda, including creative attention to education, crime, trade, and the environment.
Meanwhile, there are some initial signs that Republican efforts to add to their ranks are having results. For example:
The Lake Houston Area Republican Women's membership has grown from about 50 to 125, says Catherine A. Wheatley, the group's president and a former Democrat.
Extra volunteers had to be called in to man registration tables at a shopping center near Savannah, Ga., says state chairman Bell.