How Biden's Lead Over Trump Has Fluctuated in the Last 3 Months

Democratic presidential candidate Joe Biden's lead over President Donald Trump has fluctuated drastically in the past three months, according to RealClearPolitics' average of national polls.

RealClearPolitics (RCP) has continued to average several nationally conducted polls to show the margin between the two candidates. As the November election nears, Biden's lead has moved up and down, with large leads coming in mid-June, but decreased in September.

According to RCP, one of Biden's largest average lead over Trump came on June 24 by 10.2 points.

In one poll from June conducted by CNBC, 47 percent of respondents sided with Biden, while 38 said they'd vote for Trump, giving the former vice president a nine-point lead. This poll surveyed 800 registered voters from June 19 to June 22.

RCP's national average shows Biden's lead over Trump decreasing in mid-July, with a lead of 8.8 points.

From July 17 to July 20, The Hill/HarrisX, conducted a national poll and found Biden ahead by seven points, as 45 percent of respondents said they'd vote for the former vice president, compared to 38 percent that chose Trump. This poll surveyed 2,829 registered voters, and has a margin of error of plus or minus 1.8 percentage points.

A similar poll from mid-July, conducted by The Economist/YouGov, found similar results as Biden surpassed Trump by seven points, 48 percent to 41 percent respectively. The Economist/YouGov surveyed 1,500 U.S. adults from July 19 to July 21, and has a margin of error of plus or minus 3.2 percentage points.

Biden saw another decline in his lead over Trump towards the beginning of August, as RCP's national average shows him leading by 6.4 points on August 7.

Joe Biden
Democratic presidential nominee Joe Biden speaks on the coronavirus pandemic during a campaign event September 2, 2020 in Wilmington, Delaware Alex Wong/Getty

The Hill/HarrisX conducted another poll in early August, showing Biden out in front by three points, a decrease of four points in just two weeks. This poll surveyed 2,850 registered voters from August 2 to August 5, and has a margin of error of plus or minus 1.84 percentage points.

Another poll from early August conducted by Rasmussen Reports found Biden holding a slightly larger lead of six points, as 49 percent said they'd vote for Biden compared to 43 percent that chose Trump.

According to RCP's national average, from the end of August to early September, Biden's lead has remained around the seven-point margin.

In one study conducted by USA Today/Suffolk University, Biden was ahead of the Republican president by seven points, 50 percent to 43 percent respectively. This poll surveyed 1,000 registered voters from August 28 to August 31, and has a margin of error of plus or minus 3.1 percentage points.

A slightly more recent survey, conducted by Investor's Business Daily/TIPP found Biden holding an eight-point lead over Trump, 49 percent to 41 percent respectively. IBD/TIPP surveyed 1,197 U.S. adults from August 29 to September 1, and has a margin of error of plus or minus 2.9 percentage points.