Unfortunately, the life-blood of politics is what we try to teach our children and grandchildren to resist: peer-pressure. Serving as an independent Bernie Sanders has been highly successful at avoiding being subject to the peer-pressure that partisan politics entails, therefore he is an atypical career politician.
As in the past, candidates utilize peer-pressure to get proxies do their dirty-work and criticize opponents. Texas Rep. Joaquin Castro and Governors Dannel Malloy are specifically mentioned in the article “Hillary Clinton’s proxies ramp up attacks against Sanders” as establishment surrogates’ receiving travel expenses to stump for Hillary.
Sen. Claire McCaskill and Gov. Andrew Cuomo are mentioned, as well, for their critical remarks favoring Hillary Clinton.