A bit more than a third of likely voters in the newest Washington Post-ABC News poll — 36 percent — said they think Clinton is honest and trustworthy, compared to 45 percent who said they think that Trump is.
When we break that down by political groups, a pattern emerges.
Among his own supporters, Trump is seen as more honest than Clinton by a 16-point margin. Trump is also seen as more honest among Gary Johnson voters; only among supporters of Jill Stein is Clinton viewed as most honest. Within their own parties, Trump is viewed as more honest, by an 11-point margin. Independents see him as more honest by a 22-point spread.
Perhaps most significantly, Bernie Sanders supporters are a lot less likely to say they think Clinton is honest than Republicans who voted for someone besides their party's nominee are to say that Trump is. Only 43 percent of Sanders backers view Clinton as honest. Three-quarters of Republicans who didn't vote for Trump in the primary think he's honest. That's the biggest split in the survey, with a gap of 31 points. A majority of Sanders backers say Clinton is not honest and trustworthy, which probably overlaps with why Democrats broadly are less likely to view Clinton as honest and trustworthy than Republicans are to say that about Trump.
When primary supporters of someone besides the eventual nominee are asked who they plan to vote for in a four-way race, those who voted in the Republican primary for someone besides Trump are more likely to say they now back him than Sanders supporters are to say they will vote for Clinton.
Chris Cillizza and I have argued about whether honesty is a leading or a trailing indicator of support; that is, if people say someone is dishonest after they already aren't supporting them, or if they end up opposing a candidate because they view them as untrustworthy. I hold the former view and think that this metric is a function of Clinton's having had a bad month and having slipped in the polls. It's clear, though, that part of Clinton's current struggle in the polls is the same one we saw for Trump a month ago: Her own party is less onboard than she might like. (In August, 88 percent of Dems backed Clinton and 77 percent of Republicans backed Trump. In the most recent poll, the figures were 82 and 83 percent.)
If Clinton's poll standing improves, my theory is that her honesty numbers will, too. But Clinton would happily take the former without the latter.