The Wyoming Secretary of State has posted the July 1, 2017 registration data. Percentages are: Republican 67.11%; Democratic 17.93%; Libertarian .91%; Constitution .30%; independent and miscellaneous 13.74%.
In November 2016, percentages were: Republican 68.36%; Democratic 19.61%; Libertarian .64%; Constitution .20%; independent and miscellaneous 11.18%.
Wyoming has same-day registration. Coupled with an energy-based economy which produces greater mobility it produces huge volatility in the electorate. For example, 18% of the potential electorate for the November general election is not reflected in your November 2016 percentages. When we consider voters who are probably no longer around, new registrations may be close to 25% of the election day electorate.
In purges following the non-presidential election (e.g. 2011, 2015, 2019(?)) roughly 1/4 of registrations have been purged (or switched to the inactive roll).
In the 7/1/2016 report, prior to the primary:
R 68.49%, D 20.23%, NA 10.60%, L 0.51%, C 0.16% 207K were registered.
In the 9/1/2016 report, following the primary:
R 69.44%, D 19.80%, NA 9.99%, L 0.57%, C 0.18%, 219K were registered.
Of the roughly 12K who were added, 86% were Republican, and non-affiliated actually declined, as some changed their registration in order to vote in the primary.
In the 11/1/2016 report, just prior to the general election:
R 68.36%, D 19.61%, NA 11.12%, L 0.64%, C 0.20%, 234K were registered.
Of the roughly 15K who were added, 27.53% were non-affiliated, while Republicans only constituted 52.66%,
In the 1/1/2017 report, which included the election day registration:
R 66.56%, D 18.21%, NA 13.94%, L 0.93%, C 0.31%, 284K were registered, a 65K increase (29.6%) in four months.
Note that the non-affiliated increased by nearly 5% in this period (9.09% to 13.94%), as the non-affiliated accounted for 27.26% of the increased registrations. Of new partisan registrations, the Republican share increased relative to the two months before the election (two months before: R 53: D 17: NA 28; election day or just before: R 57, D 13, NA 27). This reflects the enthusiasm for Trump by more casual voters, who don’t vote regularly, and weren’t registered before the election.
In the 3/1/2017 report which followed the election and included purges.
R 67.11%, D 17.95%, NA 13.57%, L 0.91%, C 0.30%, 262K were registered, a 22K decrease.
Republican share increased due to fewer purged voters (these would have been switched to inactive, while those who had been classified inactive before the 2014 election and did not vote in both 2014 and 2016 would be removed completely). The March report might also have been a catching up in registrations that were switched to a different county on election day in 2016.
R -6.70%, D -8.91%, NA -10.03%, L -14.05%, C -8.75%, Overall -7.61%.
The 7/1/2016 report reflects almost no change (these are numeric changes, not percentage)
R -154, D -14, NA +340, L +7, C +4, Overall +181.
There will be few changes until 2018 when registration will increase for the primary and general election (but nowhere to the extent of a presidential election).
Votes cast in the last two election cycles:
2014 primary: 120K
2014 general: 171K
2016 primary: 114K
2016 general: 259K
If the 11/1/2016 registration reflected the size of electorate, then turnout in the general election was 110%, only possible if the the Russians hacked the election
If the 1/1/2017 election registration total is used, then turnout was a very high 91%. Wyoming is almost like North Dakota, which has no registration. In Wyoming, you can show up to vote and register at the same time. There is little reason to pre-register.