The number is not surprising given that his approval rating is at 39%. Interestingly, however, only 29% of those who vowed not to vote for Trump said they would definitely vote for his Democratic rival. That means nearly 70% of those who will not vote for Trump want to wait to see who that Democrat might be. Presumably they might vote third party, depending on the outcome.
Of those who said they plan to vote for Trump, 14% are open to the possibility but not certain, and 28% they would definitely vote for him.
These numbers indicate that, after three turbulent years, the country remains as divided as ever, with most Americans siding either with their ideological bias or pro- or anti-Trump. Perhaps the most successful candidate will be the one to appeal to the exhausted majority of voters tired of partisan politics, though in this climate such appeals will be challenging.
Despite the negative polls those hoping to see Trump voted out of office should be cautious. Pundits in 2016 were positive Trump would not get the Republican nomination, but he did. Then they were all certain he would not win the election, but he did.