PHILADELPHIA (CBS) – Economist Chris Butler talked with Chris Stigall on Talk Radio 1210 WPHT about Bernie Sanders’ attacks on Hillary Clinton, her ties to Wall Street, and the fees she’s received to give speeches to Goldman Sachs.

Butler pointed out that being paid over $600,000 to talk to Wall Street banks certainly looks suspicious from the outside.

“The perception of impropriety, it is perception of quid pro quo that I think Bernie Sanders had a problem with and I think that’s what most of the country sees when they see a politician or someone that’s still in office, someone that’s still going to run for office receive such large payments for speaking. We know darn well there is something else meant by the payment.”