She could have made the remark about white trash to joke a little about people that tend to think that people from the South and Midwest are white trash.
Anyway, she was making a little joke...saying she isn't white trash but likes sugar...get it? Sugar is white trash because it's not good for you?
I guess it's funnier if you hear her say it out loud.
But yes, let's bash Chenoweth again.
"I've got to get me out of here
This place is full of dirty old men
And the navigators and their mappy maps
And moldy heads and pissing on sugar cubes
While you stare at your books."