What does a margin of error of 3% mean in a political poll?

A margin of error of 3% in a political poll means that if the poll found that candidate A has 50% support, the true percentage of voters who support candidate A likely falls between 47% and 53% (50% ± 3%). It indicates the range within which the true population value (the actual percentage of voters supporting candidate A) is likely to lie. This should be considered when interpreting poll results and drawing conclusions about the election.