That is the best live operator poll recently for Trump.
However, re the headline numbers, I would take it with a dose of salt as this Pew Poll is modeling the electorate as being 73% white, in 2012 it was 72% white, and there is nearly unanimous agreement that this year it will be about 70% white. Pew’s own analysis earlier this year suggested the electorate will only be 69% white. http://www.pewresearch.org/fact-tank/2016/02/03/2016-electorate-will-be-the-most-diverse-in-u-s-history/ I don’t know why they used this assumption (nearly every poll weights by race as it’s an important demographic factor) but that 3-4% difference in the white vote probably cuts Hillary by 1-2%, and raises Trump by 1%. Also this poll has very high numbers for Stein and Johnson, both of which I think will fall for the reasons I have explained before as the election gets closer. No way in a “fear” election large numbers go for a 3rd party candidate, helping elect the “worst” option.
This poll though has very good numbers for Obama (now up to 53% approval, 42% disapproval) and the Democratic Party has a net +3 favorability (49% fav, 46% unfav), while the republican party has a net -18% favorability (38% fav, 56% unfav).
Pew thought has some interesting questions, asked in a different way, which I think highlight what I believe to be both candidates very different “ceilings” in the vote.
Asking if the candidate “would be a ____ President”, 31% said Great or Good, 22% Average, 12% Poor, and 33% Terrible as to Hillary. But for Trump, only 27% said Good/Great, 15% average, 12% poor, and 43% Terrible. So 55% of the electorate say Trump would be Poor/Horrible as president. Only 45% say that of Hillary. And with Hillary the issue appears to be younger voters, 75% of her supporters over 50 say “good/great” while only 63% of those under 50 say so (the sanders supporters).
Pew also asked if each candidate would “make major mistakes that would hurt the Country” and 55% said Trump would, 44% said Hillary would. These numbers line up with the “poor/Horrible” as president numbers, 55% of the electorate say Trump would be a “poor/Horrible” president and would make “major” mistakes that would harm the Country. People answering this way are NOT going to vote for Trump. Along with other polls this suggests to me that Trump’s Ceiling is about 45%. Whether we look at issues, fitness, or these questions, Trump has a hard ceiling of somewhere between about 37 and 45% of the electorate.