This year's US presidential race is transcontinental, from one side of a 3, 000-mile country to the other. But the outcome will largely be determined by what happens on a piece of real estate 10 to 20 inches wide: your television screen.
Americans today trust their own impressions of political candidates more than other people's views. Surveys find that in this electronic age, most voters no longer form those impressions by seeing politicians in person, but largely by watching them on TV. The televised picture of political reality thus has become the reality itself.
For instance, 120 million voters watched the televised 1980 debate between Jimmy Carter and Ronald Reagan - far more than would have seen the two in person had they whistle-stopped the nation from Labor Day to Election Day.
In the process television - its producers, editors, and reporters - is performing the function political parties used to do: Through selection and editing it screens the candidates, political scientist Austin Ranney notes. Gone are the days when political deals and horse-trading decided who would run for what.
Gone, too, are the days when the winner of the November race would be determined largely by appearances-in-the-flesh, such as the old whistle-stopping tours, which exited with Harry Truman's 1948 reelection race.
Because of its time and space constraints, television must sharply limit the number of candidates covered to those whom it judges to be viable. This is one reason all eight Democrats are trying to do well in the first two contests, initially in Iowa's caucuses, then in New Hampshire's primary.
After these two, TV in effect may decide that some candidates no longer have any realistic prospect of winning the nomination: Thereafter they will receive little time on the air, thus severely crimping their ability to raise funds and to get their message across to the public.
More people do get accurate information about candidates now than in the past through seeing them on television, as well as reading about them.
But that information is not always complete. ''Horse-race journalism'' - telling who's ahead - gets some five times as many minutes on TV as do items that tell what the candidates are personally like or what they stand for.
Some exceptions, such as the hour-long ''MacNeil/Lehrer NewsHour'' and the three recently televised debates among the Democrats - in New Hampshire, Iowa, and Massachusetts - yield more insight.
One of the main concerns about television's effect on elections is that some speaking styles are enhanced by TV, while others are harmed.
Those who give swift and decisive answers look best; those who speak more slowly and thoughtfully, or admit to not knowing an answer, seem indecisive.
Aided is the candidate who speaks quietly, calmly, mellifluously, as if talking personally to each voter.
Disadvantaged is the candidate who speaks expansively, with large gestures, and in a penetrating voice.
Historians rank Abraham Lincoln one of the greatest American presidents. Lincoln spoke exuberantly, in a high-pitched nasal voice, and sometimes waved his long arms like windmills. Had he campaigned in the age of television, would voters even have nominated him?