The Democratic edge in Nevada registration has been growing since the caucuses and they are far ahead of of the Republicans. The facts don't back up anything you are saying.
Of course Democrats > Republicans in Nevada.
But not as this skewed Poll
1. Nevada: CBS News/YouGov. Aug, 2-5 990 LV
https://d25d2506sfb94s.cloudfront.net/cumulus_uploads/document/z0kcmymyf0
Total 990 LV
Total 392 democratic LV (39.59%)
Total 274 republican LV (27.67%)
Democrats: +11.92%
2. Last updated: 8/1/2016 8:36 AM.
https://www.nvsos.gov/Modules/ShowDocument.aspx?documentid=4373
Total 1571775 registered voters.
Total 631742 Democrats in Nevada (40.192%)
Total 526177 Republicans in Nevada (33.476%)
Democrats: +6.716% in Nevada
DEM-REP (margins) = +5.2% overweighted
#unskewthepoll = Actually TRUMP takes the leads about +1~2% of this NV Poll.
You need a good explanation of why polls differ from year to year from valid analogies. One typically begins with the results of the previous years and looks for causes in differences from the previous year. Causes include:
1. differences in the quality of the candidates: thus Bill Clinton is not Mike Dukakis and Barack Obama isn't John Kerry.
2. effectiveness of campaigning
3. general satisfaction of people with economics and foreign events
4. demographic change within the states.
5. cultural change that might have a partisan effect.
Your argument misses those.
Mass observation and not your opinion of the candidate (think of all those partisan Democrats who said "Ronald Reagan is simply horrible" or highly-partisan Republicans who thought Obama was the worst thing to ever happen to America). Those were out of touch with America.
"No mo' Ron '84" was a bumper sticker that I remember from 1984. I saw a bumper sticker that reads "OBAMA -- One Big-A$$-Mistake-America" recently.
Ignore those.