Race to the Bottom

As most everyone who follows politics knows by now, we enter the unprecedented 2016 Presidential election with the candidates of both major parties disliked by a majority of Americans.  In this posting I examine the trends in “favorability” for both Hillary Clinton and Donald Trump.

Using the data at Huffington Post Pollster I calculated the “net favorability” for each candidate, equal to the percent of respondents saying they view a candidate favorably versus the percent who say they view that candidate unfavorably. I begin with Hillary Clinton, for whom we have favorability data dating back to 2009.



It might be hard to imagine today, but during her tenure as Secretary of State in Barack Obama’s first term, Hillary Clinton was viewed quite positively by the American public. Between Fall, 2009. and Fall, 2012, about three out of five Americans surveyed reported that they viewed Secretary Clinton favorably.  Even as late as April, 2013, Clinton was favorably viewed by 64 percent of the adults surveyed by Gallup, compared to 31 percent who viewed her unfavorably.  That translates into a net score of +33 (=64-31) in the graph above. She would never attain that level of popularity again.

Opinions about Clinton did not fall right away after the attack on the U.S. Consulate in Benghazi, Libya, on September 11, 2012, but the downward trajectory began soon thereafter.  When she announced her candidacy for President on April 12, 2015, the proportion of Americans holding favorable and unfavorable views of Secretary Clinton were just about equal.  A few months later her favorability score was “underwater,” with the proportion of Americans holding unfavorable views outnumbering those with favorable ones by between ten and twenty percent.


Opinions about Donald Trump have also remained pretty constant, and consistently negative, since he announced his candidacy on June 12, 2015.   At no time since he began his campaign for President have more Americans reported feeling “favorable” toward Donald Trump than “unfavorable.”  His ratings improved somewhat after his announcement and through the summer of 2015, but when the primary campaign began in earnest starting in January of 2016, Trump saw his favorability score fall further south.  It has rebounded and levelled off since he became the presumptive nominee after winning the Indiana primary on March 26th.  Compared to Hillary Clinton’s ratings, though, Donald Trump’s net favorability score averages about -24 compared to her average net rating of -11.


If we now take the difference between these two net favorability scores, we can see whether both candidates are equally disliked, or whether one is disliked more than the other.  For most of the campaign so far, Hillary Clinton has been winning the contest over which of them is less disliked.  Her net favorability scores generally run around 11-12 percent less negative than Trump’s.  For instance, over the month of June, 2016, Clinton averaged 41 percent favorable versus 55 percent unfavorable, for a net favorability score of -14.  Trump’s scores were 35 percent favorable and 60 percent unfavorable, for a net score of -25, or eleven points worse than Clinton’s.


As you might expect, there is a strong correlation between this net favorability score and the proportion of respondents intending to vote for Clinton or Trump.  Net favorability alone explains about two-thirds of the variance in voting intention across the 113 polls where both questions were asked.  Given the relationship shown in the graph, a score of +11 in net favorability should yield about a five percent lead in voting intention.


One interesting finding from the regression results is that the constant term of 1.06 percent is significantly different from zero.  (It has a standard error of 0.38 with p<0.01.)  The constant predicts Clinton’s lead when net favorability is zero, or in a poll where the proportion of people favoring and disfavoring each candidate is identical.  When net favorability is zero, Clinton leads Trump on average by a bit over one percent.