(See the comment by MAT on how both Democrats and Republicans benefit from a brokered Republican convention.)
Until recently, the most likely way to give someone other than Donald Trump a majority of delegates was to narrow the field of candidates drastically. But the Republicans didn’t do that in time for Super Tuesday (also see this look at the political twists and turns in the NYT). Now what?
As Marco Rubio and friends go on the attack against Trump, is Rubio about to gain new life? Or is he cooked?
Super Tuesday is just three days away. Although the 12 states that vote are not particularly strong for Trump, they could conceivably give him a majority of the delegates awarded so far.
First…let’s note that some people seem to think Rubio is still in the mix to get a substantial number of delegates.
If Rubio wins VA/MN, Cruz and Rubio both top Trump in TX, Trump looks a lot more vulnerable. Still LOTS of volatility in GOP field.
— Josh Kraushaar (@HotlineJosh) February 25, 2016
This breathless commentary suggests the feeling that candidates have risen and fallen a lot. That feeling is strongly contradicted by the data.
Candidate numbers have been anything but volatile. National surveys don’t tell us about individual states, but they do give us a barometer of public opinion. By this barometer, Donald Trump has been ahead of all other candidates since July 1 of last year. He has only accumulated support since then. And since late December, his median national support has stayed in the 35-40 percent range.
Trump’s trajectory is notably more stable than Mitt Romney’s in 2012. During the corresponding period, Romney was repeatedly overtaken by other candidates: Newt Gingrich, Rick Santorum, Herman Cain, and Rick Perry. Only in March did Romney assume a durable leading position.
Based on the graph above, it wouldn’t be surprising if Rubio’s attacks had little or no effect. Trump’s supporters seem to be quite dedicated. We will see what the coming wave of super PAC-funded ads can accomplish.
Even if there is movement, it probably won’t have much effect on Tuesday’s results. On that day, 12 states will vote to commit 624 delegates, or 25.2% of all convention delegates. Add that to the 133 (5.4%) delegates from the four early states of Iowa, New Hampshire, South Carolina, and Nevada, and that gets up over 30% of delegates. These layers of the cake are largely baked.
In early states, poll medians mostly predicted the early-state outcomes:
|Year||Trump polls||actual||Cruz polls||actual||Rubio polls||actual|
For these candidates, the average difference between polls and outcomes was 3.0 percentage points. Statistical variation would have predicted differences of just 1-2 percentage points, so there was some additional inaccuracy. Generally, all three candidates outperformed their polls: Trump by a median of 1.7%, Cruz by 2.6%, and Rubio by 3.4%. This might be because undecided voters committed at the last moment, or because of strategic voting by supporters of lower-tier candidates. Evangelical support is thought to be hard to capture in surveys, and those voters often don’t like Trump.
Whatever the reason, Cruz and Rubio have overperformed by an average of 1-2 percentage points relative to Trump. The only place where such a small difference could alter the #1 finisher is Minnesota, where one lonely poll shows a three-way tie (Rubio 23%, Cruz 21%, Trump 19%). Even that doesn’t matter since Minnesota will give them each a proportional share of delegates, which might not be altered.
In the rest of the states, Cruz is ahead in two (Texas and Arkansas) and Trump is in first place in eight: Alabama, Alaska, Georgia, Massachusetts, Oklahoma, Tennessee, Vermont, and Virginia. That would suggest some big headlines for Donald Trump on Wednesday.
Trump has attained this level of dominance with average support of only 31% in these states. That is 10 percentage points weaker than his national support. In contrast, Cruz and Rubio’s Super-Tuesday averages are within 1 percentage point of their national numbers. So Trump could do even better in the weeks ahead, especially as contests shift to winner-take-all races.
This statement from Costa glosses over the importance of the actual rules, which are pseudo-proportional. This, combined with continued division in the field of candidates, has serious implications.
Super-Tuesday support for Trump, Cruz, and Rubio add up to an average of only 69% of votes. John Kasich, Ben Carson, and undecideds make up the remaining 31%. As I have written, this division is a real problem for Republicans who oppose Trump. The reason has to do with minimum thresholds, written into state-level rules, to get any delegates at all.
Eight Super Tuesday states require a candidate to get at least 13 to 20 percent of the vote in order to get any statewide delegates. Cruz appears to be below threshold in Alabama, Georgia, and Vermont. Rubio appears to be below threshold in Alaska, Tennessee, Texas, and Vermont. And then there are Congressional district-level delegates, which account for about one-third of the delegates to be awarded. Here, the rules are even worse for runners-up: in addition to the threshold requirement, the tendency is to give two delegates to the top finisher and one delegate to the second-place finisher. At the district level, Cruz and Rubio are about equally likely to fall into the third-place abyss.
If I use current polls and feed them into the delegate selection rules using the same simulation I have previously coded, I get the following distribution of delegate totals for the 11 states that vote on Tuesday.
(Note: the following calculations were corrected on Feb. 28th to account for pledged party officials and to leave out Wyoming.)
As you can see, the number of delegates drops off fairly steeply for candidates with lower vote share. This dropoff is a direct consequence of the rules, which strongly favor the candidate with the largest fraction of the vote. Combined with early-state delegates, Trump would have a cumulative total of 369 out of 695 delegates, or 53%. So there is a very good chance that Donald Trump will end up with over 50% of cumulative delegates the end of Tuesday night.
(I also note that we now have a firm number: an average vote share of 30% on Tuesday is approximately enough to get Donald Trump 50% of cumulative delegates.)
The other estimated cumulative delegate totals are: Cruz 218, Rubio 104, Kasich 18, and Carson 11. Ted Cruz was already planning to stay in the race past Tuesday; these outcomes should ensure it.
After Super Tuesday, conditions get even tougher for Rubio. The next few winner-take-all states favor Trump. In Ohio (66 delegates), Trump holds a lead of only 3.5%, so attacks on Trump might flip Ohio – to Ohio Governor John Kasich. That would get Kasich almost caught up with Rubio in delegates. In Florida (99 delegates), Trump leads Rubio by 18 percentage points, making that race a probable humiliation to Rubio in his own home state. If indeed Kasich wins and Rubio loses, look for Kasich to stay in the race to the convention.
In light of this, the best hope for Rubio is to drive Trump’s support down by a few percentage points. It’s a desperate move, but it might delay Marco from being baked into the cake just yet.