Saturday, November 10, 2018

An Early Explanation to North Carolina's Constitutional Amendment Votes

With the final number settling in the Old North State's 2018 mid-term election, a number of analyses can be conducted with the data (with more analysis once the voter history data file is released later this month hopefully).

With six constitutional amendments on the 2018 mid-term ballots in North Carolina, a set of questions could be raised, most notably, what explains the vote pattern for the constitutional amendments (of which four of the six amendments passed)?

In thinking about the previous blog post about the impact of Trump's 2016 vote in the 2018 state legislative districts, and the fact that the Trump 2016 vote percentage explained 95 percent or more of the 2018 GOP candidate's vote in the state legislative districts, I started off by looking at the 100 county percentages for each of the 2018 constitutional amendments compared to the 2016 vote percentage for Donald Trump in the counties.

First, the constitutional amendment that had the highest vote 'for' was the victims' rights amendment, which passed with 62 percent of the vote:


Trump's 2016 County Vote Percentage explains 71 percent of the 2018 vote for the victims' rights constitutional amendment, a fairly respective 'explanation' percentage.

Next in terms of voter approval was the constitutional amendment for capping the state income tax rate at 7 percent:


Three-quarters of the income tax cap constitutional amendment can be explained by the county's 2016 vote for Donald Trump, again, a fairly respectable explanation percentage.

Next, with 57 percent of the vote, was the hunt & fish constitutional amendment:


Slightly higher than the income tax rate's explanation percentage was the hunt & fish vote, which 77 percent of it could be explained by a county's Trump vote in 2016.

Finally, the amendment that passed with the 'closest' percentage was the voter photo ID, with 55 percent of the vote:


Interesting, the most "competitive" constitutional amendment in final vote tallies had the highest explanatory percentage with Trump's 2016 county vote percentage, at 90 percent.

So, as the constitutional amendments' votes went from less competitive to competitive, Trump's 2016 vote percentage in a county could explain a greater percentage of the amendment's vote, ending with a fairly high correlation between Trump's 2016 county vote percentage and the voter photo ID constitutional amendment.

For the two constitutional amendments that the voters rejected--the judicial vacancies and the ethics and election board--the explanatory power of Trump's 2016 vote was less impressive.

With less than 40 percent of NC's voters supporting the ethics and elections board amendment, the explanatory power of Trump's 2016 performance dropped considerably in relation to the amendments that passed.


Less than half of the ethics & elections board amendment's vote (47 percent) can be explained by Trump's 2016 county vote percentage.

For the judicial vacancies constitutional amendment, which saw only a third of NC voters support it, the Trump explanation percentage was almost half:


Trump's 2016 county vote percentage could explain 49.2 percent of the vote for the judicial vacancies constitutional amendment.

So, the constitutional amendment that had the greatest explanatory percentage by Trump's 2016 county vote percentage was the voter photo ID amendment, so I decided to run that amendment's county vote percentage against the other five amendment votes to see if there was a relationship, if any, between the voter photo ID and the other five amendments.

To give a general sense, if you run the voter photo ID to itself in each county, of course, you're going to get a perfect 1.0 explanatory (meaning, a perfect 100 percent relationship):


First, the hunt & fish vote to the voter photo ID vote:



Over 92 percent of the hunt & fish vote can be explained by the voter photo ID vote.

Next, the victims' rights vote to the voter photo ID vote:


Again, over 90 percent of the victims' rights vote can be explained by the voter photo ID vote:

Next, the income tax cap vote to the voter photo ID vote:


Nearly 95 percent of the income tax cap vote can be explained by the voter photo ID vote.

Finally, the two amendments that failed and the relationship with the voter photo ID vote, first for the ethics & elections board:


Two-thirds of the ethics & elections board vote can be explained by the voter photo ID, a respectable level.

Finally, the judicial vacancies vote to the voter photo ID percentage:


Again, almost a two-thirds explanation by the voter photo ID to the judicial vacancies vote. Once we get more data from this year's election, most notably each county's voter turnout percentages by party registration, more analysis can be done. But the power of Trump's vote performance in 2016 to an election two years later shows an influential explanation for the voter photo ID percentage, and the voter photo ID amendment seems to provide a greater level of explanation for the other constitutional amendments.