Romney is a plutocrat. The point of that was to demonstrate that an enormously wealthy man wasn’t paying his fair share, and Romney couldn’t/wouldn’t prove otherwise. Does anyone have any concerns about Sanders’ wealth or tax payments? Even if he is a millionaire (seems likely to me that a 74 year old who’s been earning a good salary for years, with a large government pension probably is, at least on paper), it’s orders of magnitude different from Mr 47%.
From what I’ve seen, there’s only been two candidates in this where there’s even been any question whether or not they were multi-millionaires. Oddly, the other one was Rubio.
I think this is inevitable with such a drawn out primary system. How much more is there to say? They’ve made their positions clear, they all just keep repeating them over and over again. The Sanders statement about qualifications was just him shoehorning his stump speech into another answer. It’s what he does.