Questions about Donald Trump’s temperament have dominated recent criticisms of his candidacy for president. But two other concerns may be doing the most damage: Doubts about his qualifications for office and his honesty and trustworthiness.

Hillary Clinton has faced the most questions about trustworthiness – making it perhaps a surprise that it’s a major problem for Trump as well. Registered voters divide about evenly in the latest ABC News/Washington Post poll on who’s more honest or trustworthy. But Trump wins support from just 12 percent of those who doubt his honesty, while Clinton’s backed by 20 percent of those who doubt hers. They’re more apt to set this criticism aside.

Qualifications may be one reason. Among registered voters who don’t see Trump as qualified to be president, just 10 percent support him anyway. Clinton has far less of a problem here because, while 58 percent see Trump as unqualified, just 39 percent say the same about her.

Many express other concerns about Trump – doubts that he has the personality and temperament it takes to serve effectively, questions about his understanding of world affairs, anxiety about a Trump presidency, views that he goes too far in criticizing others and a sense that he’s biased against women and minorities. All, naturally, are related to each other, as well as to vote preferences; among those who see Trump negatively on each of these, 80 percent or more don’t support him.

Nonetheless, when we test them in a statistical model, views of Trump’s qualifications and of his honesty and trustworthiness emerge as the two items among these that carry the most weight in decisions on whether or not to support him for president.

The model also controlled for basic demographics, partisanship, ideology and presidential approval. Evaluations of Obama’s job performance join views of Trump’s qualifications and honesty as the strongest correlates of his support. Assessments of his temperament emerge as unrelated independently to preferences for Trump; the other items, while statistically significant, don’t make quite as much of a difference.

It’s possible to think of qualifications as the sum total of these other concerns; then again, it’s not often a key issue in presidential elections. Regardless, the public’s substantial misgivings about Trump’s qualifications and honesty may be particularly daunting for him given the stability of these attitudes. The number of registered voters viewing Trump as unqualified has remained nearly unchanged in the five ABC/Post polls to ask the question since last September. Similarly, in three polls asking about Trump’s honesty, the best he’s done is 39 percent among registered voters, and that was nearly a year ago.

A similar statistical analysis of support for Clinton also points toward Obama’s approval rating and views of her qualifications as top predictors; a difference is that these work to her favor given the president’s popularity and the widespread perception that she is qualified for the job. Assessments of Clinton’s honesty and temperament and anxiety about a Clinton presidency also are relevant, but less important. Her perceived knowledge of world affairs and the belief that she’s “too willing to bend the rules” do not emerge as independently related to her support, given these other factors.

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