in my opinion This Poll(Ohio) YouGov/CBS 5/16-5/19 overweighted democrats too much
and underweighted Independents too much.
About the details, My Analysis
1. Demographcis of Ohio in 2016.
1) Population: 11.6 Million
2) Registered Voters (Post March,2016)
http://www.athensmessenger.com/news/more-than-locals-switched-political-party-affiliation-in-primary/article_0cbe0d02-e83a-5617-91ae-e6aac1ead07f.htmlTotal: 7.61 Million Registered Voters
Republican: 2.26 Million ( 29.7%)
Democrats: 1.44 Million (14.9%)
Independents: 3.91 Million ( 51.4%)
2. Put the Poll Results to Realistic Party Affiliation Demographics
YouGov/CBS Poll(Ohio) 5/16-5/19, 990 LV. Page 13
https://www.scribd.com/doc/313450292/CBS-News-2016-Battleground-Tracker-Ohio-May-22
Calculation
1) TRUMP
Rep(29.7%) x 80% + Dem(14.9%) x 6% + Ind(51.4%) x 39% = 44.69%
2) Hillary
Rep(29.7%) x 4% + Dem(14.9%) x 82% + Ind(51.4%) x 37% = 35.91%
Totally different with Poll Results which was Hillary 44% TRUMP 39%