Reply #2: Ras's explanation is clear [View All]

Since April, Giuliani has led Clinton several times in Rasmussen Reports national polling, but usually by no more than three percentage points. In mid-August he led by seven, but by September he was trailing. On October 9 Giuliani trailed Clinton 41% to 48%. In the next poll he managed to edge out Clinton by two points, but on November 11 he was again trailing, by six (see history).

Individual polls can sometimes overstate volatility in a race, especially when the results carry a four percentage point margin of sampling error. One way of addressing this is to look at a rolling-average of three consecutive polls. Using this approach, Clinton and Giuliani have both been within two points of the 45% mark for thirteen consecutive polls dating back to May 1, 2007. The candidates have been within two points of each other on eight of those thirteen surveys.

Currently, the three-poll rolling average shows Clinton and Giuliani tied at 45%. Clinton had held the advantage in the last four updates of the three-poll rolling average. At the beginning of the campaign, Giuliani had the advantage--during the first eight sets of three-poll averages, Giuliani was “ahead” in seven and tied with Clinton in the eighth."