According to this poll, it’s Asians and HIspanics who believe in hard work, Blacks who don’t, and Whites in between:
https://www.pearson.com/content/dam/one-dot-com/one-dot-com/global/blogs/2016/03/Next-America-Poll-San-Antonio-16.jpg
According to this poll, fewer Americans today believe there are opportunities to get ahead, than in the past.
http://content.gallup.com/origin/gallupinc/GallupSpaces/Production/Cms/POLL/gsooy1_te0ut9gcw3b8zrw.png