Presidential Polling Since the "Trump-Tapes"

This is a quick data note. Since the release of the vulgar "Trump Tapes" from 2005, there has largely been a perception that Trump is out of the race, with unsubstantiated (and subsequently refuted) rumors of Pence dropping off of the ticket. Indeed, he has been abandoned by even more Republicans (many "establishment" Republicans had already refused to support him prior to this). However, current polling doesn't necessarily indicate a voter groundswell different from the weeks prior to the release of the tapes.

I've been struggling with how to create an easy-to-read graph of the polling of these changes. On the one hand, the polling has been reasonably consistent that Clinton has a far better chance of winning the electoral vote than Trump, even prior to the release of the tapes. As of October 3rd, Nate Silver's forecast gave Clinton a 72% chance of winning. The tapes came out Friday, Oct 7th, and post-release polling largely wouldn't have been released until either Monday or Tuesday. To be safe, I looked at polling released starting on Tuesday, Oct 11th. The graph I created shows 4 time periods-the first is the Romney-Obama election win margins of 2012, the second is 2016 polling up through Sept 28 (the first debate), the third time-period is from Sept 29-October 10, and the last is polling since Oct 11th. Negative values (below the 0 mark) represents a lead for Republicans, and positive values (above 0) represent a lead for Democrats.

Comparing the Obama-Romney win to pre-October polling, Utah, Texas and Arizona are the most obvious "Republican" states who shifted the most. This was up to and including results from the first presidential debate, and all show fairly radical shifts towards Clinton. Some other states, like North Carolina, Virginia, Michigan and Maine also showed some movement, with NC & VA showing movement in Clinton's direction, while MI and ME showing moves towards Trump. Somewhat more surprisingly, the Utah, Texas and Arizona shifts seem to be holding as of October 15th polling, even shifting further towards Clinton--AZ continues to poll (narrowly) for Clinton, and the NC polling for Clinton is even stronger. Whereas Romney won TX with a 38% margin, Trump has been polling with only a single-digit, decreasing lead. Other states, like Michigan and Maine, are firmly now in the Clinton camp.

However, the Trump tapes so far are not showing a large impact in these specific states. The graph only includes states where polling has been done since Oct 11th. While there does seem to be some movement in Clinton's direction in several states, the change is slight, and within the margin of error in every case except Michigan. In fact, Florida, Pennsylvania & Wisconsin evidenced a shift in Trump's favor from the two-week period after the first debate, but before the release of the Trump tapes, to the week following the release of the tapes (these shifts are also within the margin of error, but at least 2% in Trump's favor--certainly not the expected shift towards Clinton following the tape release).