How might the presidential debates affect the polls?

According to ElectoralVote, Hillary Clinton currently leads in states worth a total of 298 Electoral Votes (EVs), Donald Trump leads in states worth a total of 236 EVs, and Maine (four EVs) is tied.

Last week, Clinton led the Electoral College by 274-258, with Nevada (six EVs) tied.  Since last week, New Mexico, Florida and Colorado have switched from Trump to Clinton leads, North Carolina from Clinton to Trump, Maine from Clinton to tied, and Nevada from tied to Trump.  

Above is this week's Electoral College map from ElectoralVote.

ElectoralVote has dumped the Ipsos 50-state Internet panel polls, as they often diverged markedly from other state polls.  As a result, New Mexico moved from a double digit Trump lead last week to a nine point Clinton lead.  New Jersey and Rhode Island (18 total EVs) were last polled by a robopollster with a strong Trump skew, and are probably much safer for Clinton than they currently appear.

But Clinton’s Electoral College position is fragile.  She currently leads by five points or more in states worth 206 EVs (dark and light blue states), while Trump leads by five points or more in states worth 180 EVs (dark and light red states).  If Clinton wins Florida (29 EVs), where polls have varied between narrow Clinton and Trump leads, it would be very hard for Trump to win.

However, if Trump wins Florida and other states where he currently leads, Clinton needs to win all other states where she is currently leading, some by one-four points.  If Clinton lost Maine, she would still win one EV from the more urban House district, and win the Electoral College by a bare 270-268 (Maine awards one EV to the winner of each of its House districts).

The Huffington Post Pollster aggregate has Clinton leading with 41.9%, Trump at 39.3%, Libertarian Gary Johnson at 8.6%, 6.6% undecided and 3.6% for Others, including Green Jill Stein.  Last week, Clinton led by 42-39.1%  Pollster aggregates give Trump a 61% unfavourable, 35% favourable rating (58-39 last week) and Clinton a 56% unfavourable, 41% favourable rating (56-42 last week).  Obama continues to have a 50% approve, 47% disapprove job performance rating.

The Presidential Debates

There will be three debates between Clinton and Trump, and one involving the Vice Presidential candidates, respectively Tim Kaine and Mike Pence.  Other candidates will not be participating as they failed to clear the 15% threshold in national polls.  The Presidential and Vice Presidential debates are each 90 minutes long, and are broadcast without any commercial breaks.  In Australia, it appears that ABC 24 will broadcast the debates.

The first Presidential debate will take place at 11am Australian Eastern Standard Time tomorrow.  The Vice Presidential debate is on 4 October, the second Presidential debate on 9 October, and the third Presidential debate on 19 October. These three debates will happen at 12 noon on the 5, 10 and 20 October Australian Eastern Daylight Time (daylight saving starts in the south-eastern Australian states on 2 October).

In the first and third Presidential debates and the Vice Presidential debate, both candidates will stand at lecterns, and be questioned on various topics by a moderator.  There will also be some interaction between the two candidates.  The second Presidential debate will be in a Town Hall format, and undecided voters will be able to question the candidates.

Polls of debate viewers will be released soon after each debate finishes.  These polls are proper scientific polls, and will give a good indication of who the public thought won.  We will then need to wait at least a few days to ascertain what effect, if any, the debates had on voting intentions.

In previous Presidential elections, the debates have not had a major impact.  Mitt Romney erased the lead of Barak Obama in 2012 after Obama’s poor first debate, but this bounce did not last, and Obama won comfortably.  According to US polling analyst Nate Silver and his colleagues, only the 1980 debates have had a big impact on the election.

The debates this year could have a larger than normal impact because there are more undecided and third party voters.  Most people voting for third party candidates are doing so as they dislike both major party candidates, and they could return to a major party candidate if one of those candidates performs strongly in the debates.

I think Trump should try to appear Presidential; this means staying calm, and not using gratuitous insults.  Clinton should try to needle Trump into losing his temper.  She also needs to appeal to young people, who are far more likely to vote for third party candidates since they dislike both Clinton and Trump.

Clinton is far more knowledgeable on the various issues than Trump and this should help her.  However, Trump could benefit from media expectations: if he does not say anything outrageous, the media could say he won because he beat expectations.


Dr Adrian Beaumont

Election Watch polls analyst


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