These 8 words spell big trouble for Bernie Sanders

That's Massachusetts Sen. Elizabeth Warren describing a December 2018 conversation she had with Vermont Sen. Bernie Sanders in advance of their respective decisions to run for president in 2020.

Which, wow. Those eight words are very problematic for Sanders -- particularly since they seem to run counter to his long-stated support of women running for all sorts of offices. That all of this is happening less than three weeks before the Iowa caucuses is even more potentially damaging for Sanders -- particularly because he was clearly building momentum in Iowa -- and beyond -- in recent months.

Sanders' campaign has had a series of reactions to this revelation since CNN's MJ Lee broke the news on Monday.

"It is ludicrous to believe that at the same meeting where Elizabeth Warren told me she was going to run for president, I would tell her that a woman couldn't win," Sanders said in a statement to CNN. "It's sad that, three weeks before the Iowa caucus and a year after that private conversation, staff who weren't in the room are lying about what happened."

Following the story being published, Sanders campaign manager Faiz Shakir said this: "We need to hear from [Warren] directly, but I know what she would say that it is not true that it is a lie." And then, once Warren came out confirming that it wasn't a "lie," Sanders senior adviser Jeff Weaver told CNN's Chris Cuomo that "there's some wires crossed here, but clearly Bernie Sanders did not say that a woman can't win."

Here's the problem with all of those explanations: Warren said it did happen. It's right there in her statement; "I thought a woman could win; he disagreed."

Now, is it possible -- as Sanders' allies have suggested -- that this was simply a big misunderstanding? That Sanders was talking about in broad terms about the sort of campaign Trump would wage and the sort of nominee that would work best -- and the sort that would work less well? I mean, I guess?

The issue there is actually two issues:

1) Sanders is saying that Warren didn't hear what she said she heard

2) At the time of this meeting it was very clear that both Sanders and Warren were very likely to run for president. So, it's pretty hard to talk in purely hypothetical terms when that's the backdrop of the meeting.

So, yeah. It's sort of hard to just call this all a big misunderstanding. Or to dismiss it -- as Sanders speechwriter David Sirota suggested the campaign would do.

"Note: Our campaign doesn't get deterred by bullshit stories that are thrown at us," he tweeted on Monday. "We stay focused on the huge crises we face — and that will never change. Onward."

Obviously, it will be up to Democratic voters to decide whether or not they agree with Sirota's assessment. But it's hard for me to imagine that Democrats deciding between Sanders and Warren in the run-up to the Iowa caucuses on February 3 won't want more of an explanation from the Vermont senator than just that this is all one big misunderstanding.

The question in my mind is whether Warren pushes Sanders for answers in tonight's CNN debate in Iowa. If Warren directly confronts Sanders on his campaign's contention that what she remembers about that conversation is not actually what happened, what will he say? And if he stands by the one-big-misunderstanding argument, will Warren let that be the last word? Or will she push for more?