A computer projection which takes into account the most recent state and national polls, as well as the weight of endorsements, identifies Donald Trump as the leader for the Republican Party nomination. More specifically, the computer model now gives Trump a 39.66 percent chance of winning the nomination. Marco Rubio is seen as the second likeliest winner, with a 26.81 percent chance. Ted Cruz comes in third with a 20.08 percent chance, and finally John Kasich is the fourth likeliest winner with a 13.45 percent chance at the GOP nomination. These projections take into account a flood of polls released today and yesterday from CBS News, Bloomberg, Monmouth, South Carolina House GOP, Emerson, NBC News/Wall Street Journal, USA Today/Suffolk, and Quinnipiac.
The algorithm works by giving a certain weight to a number of factors in calculating the odds that each candidate will eventually win the Republican Party nomination. The heaviest weight, 30 percent, is given to the New Hampshire primary, which has tended to be the most predictive contest over the last 20 years. Other factors included are polling of the Iowa Caucus (20 percent), South Carolina primary (10 percent), and nationwide polling (20 percent). Finally, to account for the effect of the party establishment and super delegates a 20 percent weight is given to the number of endorsements candidates have received using FiveThirtyEight’s measurement of official endorsements for each candidate.
At this time only Donald Trump, Ted Cruz, Marco Rubio, and John Kasich are included in the calculations, as all other candidates finished poorly in Iowa and New Hampshire, or are polling to poorly among the general electorate to be considered a serious threat for the nomination.
The benefit from the Iowa Caucus is not the delegates themselves, which is relatively minor in the overall total, but instead in the positive media coverage which comes from finishing above or below expectations. The results of the Iowa Caucus are now well known. Trump dramatically underperformed compared to his poll numbers while Ted Cruz’s ground game turned out a superior vote total allowing him to place first. Marco Rubio also exceeded expectations by finishing third. Since both Rubio and Cruz exceeded expectations and received positive media coverage each was given 50 percent credit for the Iowa Caucus, while Trump received zero percent.
Donald Trump was the overwhelming winner of the New Hampshire primary and received very positive media coverage as a result. The other beneficiary of the New Hampshire primary was John Kasich, who exceeded expectations by finishing second and also gained positive media coverage. Given these results, Trump was given 75 percent credit for the New Hampshire primary and Kasich was given 25 percent credit.
The next crucial contest is in South Carolina on Saturday.
A Real Clear Politics average of six polls released in South Carolina over the last three days currently has Trump as the leader at 34.5 percent, compared to 17.3 percent for Ted Cruz, 16.8 percent for Marco Rubio, and 9.7 percent for Kasich. If these polling results are accurate, Trump will win South Carolina, giving him even more momentum heading into the crucial Super Tuesday primary states on March 1.
The polling also favors Trump on Super Tuesday. The Real Clear Politics average of nationwide polling currently has Trump leading with 33.8 percent support, compared to 21.0 percent for Cruz, 16.3 percent for Rubio, and 8.8 percent for Kasich. Trump has undoubtedly benefited from the tremendous amount of free media coverage he has received over the last few months and it shows in the current state of nationwide polling. At this time, Trump and Cruz have clearly distinguished themselves from the field nationally. Marco Rubio will need to gain national coverage in the coming two months to make up the gap on Cruz and Trump, but it is hard to see that happening if Rubio cannot exceed expectations in South Carolina.
Finally, the reason Marco Rubio is still in the race despite not finishing better than third in Iowa and New Hampshire the party establishment factor. As documented at FiveThirtyEight.com, citing a study done by four prominent political scientists, significant endorsements from members of the party tend to cause success in primary states. In previous elections the party elites tended to favor one candidate ahead of the Iowa Caucus and New Hampshire primary, and that candidate tended, with few exceptions, to go on to win the party nomination. Using Silver’s measurement of endorsements, which gives more weight to endorsements from U.S. Senators and state governors than U.S. Representatives, Marco Rubio currently leads the endorsement race among the top four contenders with 85 endorsement points. Coming in second is Ted Cruz with 21 points and John Kasich comes in third with 20 endorsement points.. Donald Trump currently has no endorsement points.
Some may be surprised that Trump is not more of a favorite to win the Republican Party nomination given his lead in many polling areas, and his lead in nationwide polling.
The reason Trump is not even more of a favorite at this point is that polling tends to fluctuate wildly in the months before and after the Iowa Caucus. Many voters still are not paying attention to the 2016 presidential race, and may change their mind in the coming months. At this point in 2012 Newt Gingrich was leading nationwide polling of Republican voters. For all these reasons other candidates, including Rubio, are still given a good chance of overtaking Trump in the polls in the coming weeks and months.
Right now when putting in the numbers and weighting each contest to the best of our knowledge Rubio is the favorite, but other candidates still have more than a fair chance to grab the Republican Party’s presidential nomination.