What Paul Krugman seems to be doing is helping the establishment that the New York Times is connected to... what's interesting is that what he seems to be doing (muddying the issues with false logic to help his chosen special interest group) has been going on for a long time.
First some background information for the context of Paul Krugman's & the New York Times views;
Now lets begin with a short rebuttal of key points in Paul Krugman's latest dishonest hit job on Sanders (Paul Krugman's words are in bold italic and my response is next)
Paul Krugman: Sanders Over the Edge
But in any case, the way Mr. Sanders is now campaigning raises serious character and values issues.
Sanders took his views from a report by Greenpeace. That's not dishonest, that is a mistake. Calling it dishonest is a lie or proof Paul Krugman is an idiot. Either one is fine with me BUT those ARE the ONLY two realistic choices.
That said, if Bernie Sanders hasn't even tried to make the case that Wall Street campaign donations haven't distorted her position DESPITE A VIDEO OF ELIZABETH WARREN SAYING THAT VERY THING! (see above) Then I will be very disappointed. Here is the video again proving Hillary's connections to Wall Street HAVE distorted her positions in the past;
But Mr. Sanders wasn’t careful at all, declaring that what he considers Mrs. Clinton’s past sins, including her support for trade agreements and her vote to authorize the Iraq war — for which she has apologized — make her totally unfit for office.
The Hillary Clinton Chronicles
Article; We need to set Paul Krugman straight about Bernie: Pundit’s latest Sanders hit job misses the entire point of his campaign Bernie hasn't become a "Bernie Bro" by attacking Hillary — he's addressing the concerns of a large bloc of voters