Hillary Clinton delivers a "low blow" to Bernie Sanders.

"Low blow" is his term.

ADDED: Here's the text of that clip:

CLINTON: [Y]ou know, today Senator Sanders said that President Obama failed the presidential leadership test. And this is not the first time that he has criticized President Obama. In the past he has called him weak. He has called him a disappointment. He wrote a forward for a book that basically argued voters should have buyers' remorse when it comes to President Obama's leadership and legacy. And I just couldn't agree -- disagree more with those kinds of comments. You know, from my perspective, maybe because I understand what President Obama inherited, not only the worst financial crisis but the antipathy of the Republicans in Congress, I don't think he gets the credit he deserves for being a president who got us out of that, put us on firm ground, and has sent us into the future. And it is a -- the kind of criticism that we've heard from Senator Sanders about our president I expect from Republicans. I do not expect from someone running for the Democratic nomination to succeed President Obama.

SANDERS: That is... Madam Secretary, that is a low blow. I have worked with President Obama for the last seven years. When President Obama came into office we were losing 800,000 jobs a month, 800,000 jobs a month. We had a $1.4 trillion deficit. And the world's financial system is on the verge of collapse. As a result of his efforts and the efforts of Joe Biden against unprecedented, I was there in the Senate, unprecedented Republican obstructionism, we have made enormous progress. But you know what? Last I heard we lived in a democratic society. Last I heard, a United States senator had the right to disagree with the president, including a president who has done such an extraordinary job. So I have voiced criticisms. You're right. Maybe you haven't. I have. But I think to suggest that I have voiced criticism, this blurb that you talk about, you know what the blurb said? The blurb said that the next president of the United States has got to be aggressive in bringing people into the political process. That's what I said. That is what I believe.President Obama and I are friends. As you know, he came to Vermont to campaign for me when he was a senator. I have worked for his re-election. His first election and his re-election.  But I think it is really unfair to suggest that I have not been supportive of the president. I have been a strong ally with him on virtually every issue. Do senators have the right to disagree with the president? Have you ever disagreed with a president? I suspect you may have.

CLINTON: You know, Senator, what I am concerned about, is not disagreement on issues, saying that this is what I would rather do, I don't agree with the president on that, calling the president weak, calling him a disappointment, calling several times that he should have a primary opponent when he ran for re-election in 2012, you know, I think that goes further than saying we have our disagreements. As a senator, yes, I was a senator. I understand we can disagree on the path forward. But those kinds of personal assessments and charges are ones that I find particularly troubling.

IFILL: Senator, if you would like respond to -- you may respond to that but it is time for closing statements and you can use your time for closing statements to do that.

SANDERS: Well, one of us ran against Barack Obama. I was not that candidate.

ADDED: I felt motivated to put that through a "readability score" calculator. There just seemed to be a distinctively different style of expression that I thought would show up. The text of Hillary's spoken word is above the 11th grade level. Sanders is just under the 7th grade level.

Here's a post of mine from October 2008, about a debate between Obama McCain. Obama spoke at the 9th grade level and McCain at the 7th grade level. And in the VP debate, Biden was at 7.8 and Palin at 9.5. At the time, I said:

Now, of course, speaking is different from writing. You edit writing, and you get to think about whether you want to be expansive and sesquipedalian or whether you want to adhere to Strunk & White rules like "Omit needless words" and "Avoid fancy words." Speaking is harder to control. You may find yourself babbling or losing your place and wondering how am I ever going to bring this sentence in for a landing, and you don't get to go back and break it up into separate sentences and cut the filler. So the seemingly higher level of speech that tests at a higher level does not necessarily represent higher brain power. Nor can we say that the man speaking at the lower level has a lower capacity for complex thoughts. He may be applying a fine intelligence to composing his sentences well.

I think if you have a good emotional connection with people either high or low can work. If you have a bad emotional connection, both high and low fail, but for different reasons.

But 7th grade is not a very low level for political speech. Apparently, Trump goes down to the 4th grade level:

The Republican candidates — like Trump — who are speaking at a level easily understood by people at the lower end of the education spectrum are outperforming their highfalutin opponents in the polls....

Mike Huckabee and Jim Gilmore, who are struggling in the polls, are both spinning sentences above a 10th-grade level, according to the algorithm. Ben Carson, who has surged and maintained a second-place standing in the polls, communicates with voters at a sixth-grade level — despite a medical degree and career as a brain surgeon.

Among Democrats, Hillary Clinton’s speeches are just right for eighth-graders; Bernie Sanders’s strong critiques of Wall Street and American capitalism are aimed higher, at the 10th grade.

I'm quoting an article in the Boston Globe from last October, which finds an explanation for Bernie's 10th grade level speech. I wonder how they'd react to Bernie now being down at 7th grade and Hillary all the way up to 11th grade. You can explain anything, of course. Once you know what happened, you can say why. It doesn't have to be true. What happened happened.

The previous 4 sentences are written below the 4th grade level, by the way.

By every criteria in the algorithm, Trump is speaking at the lowest level. He used fewer characters per word in his announcement speech, fewer syllables per word, and his sentences were shorter than all other candidates.
His vocabulary is filled with words like “huge,” “terrible,” “beautiful.” He speaks in punchy bursts that lack nuance....