A Fox News Poll of 649 likely voters in Alabama released on Thursday and conducted between Monday and Wednesday of this week shows Democratic candidate Doug Jones with an eight-point lead over Republican candidate Judge Roy Moore in the December 12 special election for the Alabama U.S. Senate seat once held by Attorney General Jeff Sessions, 50 percent to 42 percent, with a 3.5 percent margin of error.

That poll stands in striking contrast to a Fox10/Strategy Research poll of 3,000 likely voters in Alabama released on Wednesday and conducted on Monday of this week that shows Moore with a six-point lead over Jones, 49 percent to 43 percent, with a two percent margin of error.

The 14 point differential between the two polls conducted over the same three day period contributes to the great uncertainty surrounding the election thrown into chaos by unsubstantiated allegations of sexual harassment made against Judge Moore over the past week by several women.

The Real Clear Politics Average of Polls, which includes those two polls as well as three recent additional polls, shows the race is a virtual tie, with Moore having an eight-tenths of one-percent lead.

One possible explanation of the wide variance between the two most recent polls may be found in the different sampling and party affiliation weighting techniques used by the different firms.

The Fox News Poll sample of 649 likely voters included 48 percent Republicans, 42 percent Democrats, and ten percent independents, which appears to be an unusual oversampling of Democrats and undersampling of Republicans.

Party affiliation of the Fox10/Strategy Research Poll was not included in the story announcing its results, but another poll included in the current Real Clear Politics Average of Polls conducted by Opinion Savvy on November 9, which showed the race to be a tie, has a very different weighting by party affiliation than the Fox News Poll.

The Opinion Savvy Poll conducted on November 9 of 515 likely Alabama voters included 58 percent Republicans, 29 percent Democrats, and 13 percent independents.

Another unusual aspect of the Fox News Poll released on Thursday that shows Democrat Jones with an eight-point lead over Moore is that it appears to contain a sample of Alabama likely voters in which 51 percent voted for Donald Trump and 48 percent voted for Hillary Clinton in the 2016 presidential election.

This calculation is arrived at by examining the results of question number eight in the Fox News Poll, which shows that 49 percent of likely voters in Alabama have a favorable view of President Trump, while 48 percent have an unfavorable view.

Among Trump voters in the Fox News Poll sample, 91 percent had a favorable view of President Trump, while eight percent had an unfavorable view of President Trump. Among Hillary Clinton voters in the sample, six percent had a favorable view of President Trump, while 91 percent had an unfavorable view of President Trump.

On election day in 2016, President Trump defeated Hillary Clinton in Alabama by a 63 percent to 35 percent margin.