Sunday, May 15, 2016

Does Donald Trump Really Have a 30% Chance of Winning?

Kevin Drum writes at Mother Jones, Does Donald Trump Really Have a 30% Chance of Winning?. He points to two articles that are both worth reading in full.

In the first, Trump expands the battleground…to Utah and the Deep South, Sam Wang points out

Historically from 1952 to 2012, the likely range of movement in two-candidate margin from this time until Election Day has been 10 percentage points, which is the standard deviation from the 16 past elections. Therefore, even though Clinton currently leads by a median margin of 7 percent (12 national surveys) and would certainly win an election held today, she could still lose the lead, and from a purely poll-based standpoint, is only narrowly favored to be elected President in November (probability: 70%).

It is also the case that Clinton is the only candidate who is poised for a blowout. Her “plus-one-sigma” outcome (current polls plus one standard deviation) is a popular vote win of 58.5%-41.5%. Trump’s plus-one-sigma outcome is a narrower win, 51.5%-48.5%.

He goes on to do his electoral college math and compares current state polls against 2012 election results finding only UT to be an outlier and otherwise a slight Democratic shift from Obama-Romney. The closest thing to an anti-Hillary state of the 15 tossups is NY, which is Trump's home state and even there Hillary is +20% while being -8% off Obama's results.

Every prognosticator at this point says that the election is far off and lots of things can happen, so we shouldn't be looking too closely at polls at this point. James Wimberley in Lies, damned lies and election statistics, looks at ": what reasonably foreseeable factors are capable of changing voters’ preferences for Trump or Clinton between now and the election?" He makes up a numerical estimate of risk factors which I ignore, but I found his (lite) analysis of ten factors a pretty interesting read.


Richard said...

The one item that I think is missing from the list and has a not insignificant chance of occurring is a third party run on either side of the race. Would Senator Sanders be so bold as to try a run as a third party candidate. I think that could have a significant draw off of Secretary Clinton's supporters. Are there "establishment" republicans thinking of a third (fourth) party race? I thought I saw a not reliable news item on Governor Romney gathering something. On that side it would only hurt Mr. Trump.

I don't think these are highly probable, but they are plausible and have been discussed in the media, but lacking in Wimberly's "Lies, damned lies and election statistics" list.

Howard said...

Agreed there is a small chance, but I don't see it happening. Here's the latest article I've seen on it.
Inside the GOP effort to draft an independent candidate to derail Trump

On the left, anyone who doesn't like Hillary has to realize that running would hurt her and increase the chance of Trump. Bernie must know that, and has said, on her worst day she's 1000x better than Trump, so I don't see him running. Bloomberg went through the same calculation, that his running would pull more votes from her. On the right, I can't see anyone thinking a run would succeed, merely that it would hurt Trump enough to elect Hillary. I don't see anyone actually wanting to do that, as it would then end their GOP career (both because they would be viewed as electing Hillary and because Trump would savage them as he has all his other rivals).