The sample size in the state polls were much smaller than the national sample.   The average margin in the popular vote polls were within a percent of the actual vote. 
Polls vary in their methodology in how they survey the population and the corrections 
for possible sample bias.  If you look at the average you see that note even the most Republican biased poll, Rasmussen shows Trump's disapproval is 56% vs 43% approval.  You can also see that Trump's approval has trended downward and disapproval has gone up since the inauguration:
https://www.realclearpolitics.com/epolls/other/president_trump_job_approval-6179.html