PNC Wealth Management did a survey of millionaires* and found that 44% of them would either strongly or somewhat support "raising taxes on the top income earners" as a way to address inequality.
This answer had the lowest support out of the four options, but still comes out to nearly half of this group of wealthy people supporting higher taxes on themselves (assuming of course they recognize that they are, in fact, the top income earners). Nearly 70% support giving to charities focused on poverty or hunger. 64% support scholarship opportunities for children from low income families, and 49% support raising the minimum wage.
Here's the slide from PNC's presentation:
PNC Wealth Management
* Defined as adults who have investible assets over $1 million. Also note that there is a +/- 6% margin of error in the sample.