As the fourth week of the fall campaign begins -- with five weeks to go -- the candidates might appear to be darting aimlessly about the political map like water bugs.
But what actually takes place is an informed pursuit of states with close margins where the election could be won or lost, or forays to soften an opponent's home base.
The candidates' sophisticated radar, their polling operations, send back almost daily reading of targets of opportunity.
This week, Republican Ronald Reagan will hit a series of his "in doubt" or "leaning" targets, including Tennessee, Florida, and Louisiana, which lie in President Carter's native South. Then he will head for Missouri, a Carter state in 1976 but a tossup in 1980. And from El Paso, Texas, he will beam into neighboring New Mexico to shore up that slipping Reagan state.
Mr. Carter, meanwhile, will head to the West Coast, where his strategists tell him he can make gains in Mr. Reagan's native California as well as in Oregon and Washington. And John Anderson will work his way east along the pivotal industrial state axis from Chicago to Philadelphia and New York.
In a regional breakout of candidate electoral strength, Democrat Carter appears to be in serious trouble everywhere, but most notably in the South, where he won the election in 1976.
A regional count, based on GOP, Democratic, and independent surveys and sources, gives Reagan an 89-to-4 electoral vote edge over Carter in the West, with 9 electoral votes in doubt. Reagan leads in the Midwest 91 to 22 in electoral votes, with 32 in doubt.
Among the South and border states, Carter leads 86 to 46, with 34 electoral votes in doubt. And in the East, Carter leads Reagan by 21 to 7. But with 97 votes in doubt in Pennsylvania, New York, New Jersey, Connecticut, and Maine, the entire region appears up for grabs.
Analysts and opponents agree the 1980 race will be decided by possibly minuscule margins, including the South, where Carter built a 1.7 million vote margin in 1976.
Even in 1976, Carter carried only two Confederacy states -- Arkansas and Georgia -- with more than 60 percent of the vote, analyst Richard Scammon points out, and he took 4 others with less than 55 percent of the vote. He carried Mississippi by just 14,000 votes Louisiana by 74,000 votes.
In 1980 at this point, on ly Georgia, West Virginia, the District of Columbia , and possibly Arkansas, Mississippi, and North Carolina are rated strong Carter states.
In a close race, John Anderson will be a factor in the South. That factor though is likely to be less powerful than in East, where his presence puts New York State's 41 electoral votes in doubt.
Proportionately, "Anderson might hurt Carter more in the South" than outside, Scammon says. In Mississippi, Florida, Louisiana, Texas, and Virginia -- accounting for 72 electoral votes -- there are few liberal or moderate Republicans. But an Anderson draw from Carter among liberal or moderate Democrats, even taking just eight electoral votes from Carter to seven from Reagan, could prove decisive, given the anticipated close votes.
Nationally, Anderson hurts Carter in states such as Massachusetts, New York, and Ohio, where Carter's margin might be the smallest, Scammon says. In 1976, Carter won Missouri by 71,000 votes, Texas by 124,000, Wisconsin by 35,000, and Ohio by 11,000 votes.
Thus the public watching Campaign '80 as the midpoint of the final stretch nears can observe the candidates homing in on the points where the margins are closest.
On the Reagan electoral screen only Hawaii in the West is leaning to Carter. But the Republican road show will follow close on Carter's this week in four states leaning for Reagan -- Colorado, Washington, Oregon, and California.
In the Midwest, both Carter and Reagan strategists now see Missouri and Michigan as tossups. They rate Minnesota strong for Carter, and Nebraska, Kansas, and Indiana strong for Reagan.
In the South and border states, the Reagan camp claims a "leaning" advantage in Oklahoma, Texas, Virginia, and South Carolina. They and the Democrats see Carter strong in Mississippi, Georgia, West Virginia, and with the edge in Arkansas, Florida, and North Carolina.
In the East, Reaganites claim a faint margin in Pennsylvania, New York Jersey , and Maine, states some Democrats and neutral observers would put into the doubtful category along with New York and Connecticut. Carter is rated strong in Massachusetts and Rhode Island, with Delaware leaning to Carter.