Let me start this off by saying I am neutral in this primary. What's more, I will permanently remain neutral in this primary. That will never change.

But I also want to take a moment to say why I think the main argument used against Sen. Bernie Sanders in the Democratic primary has, at least to date, failed. The grand arc of this campaign has been a long, slow rise for Sanders in Iowa , New Hampshire and nationally . The arguments against Sanders have proven to be ineffective to change the course of this arc.

As nearest as I can tell, the main argument against Bernie Sanders is as follows.

The policies Sanders proposes do not have a realistic chance of becoming law, even if Sanders were elected POTUS.

This is why almost all prominent progressive wonks, advocacy organizations and congressional Democrats have endorsed, or at least lean toward, Sec. Hillary Clinton.

Additionally, when Sanders is challenged on this point, his campaign and his supporters have responded with a frothing, unbecoming anger that reinforces the perception that they are politically naive and unwilling to do the coalition building and make the compromises required to actually get things done.

Paul Krugman, via our own brilliant Brainwrap, summed this feeling up pretty well the other day (full disclosure: I think Brainwrap is a genius):

Meanwhile, the Sanders skepticism of the wonks continues: Paul Starr lays out the case. As far as I can tell, every serious progressive policy expert on either health care or financial reform who has weighed in on the primary seems to lean Hillary. This could be because being in the trenches of the health care fight gives you an acute sense of the possible, and because having paid close attention to the financial crisis makes you a shadow-banking, not too big to fail guy. Or it could be because they are, one and all, corrupt corporate lackeys. I report, you decide.

In short, Sanders is not making realistic policy proposals, and his supporters are being angry and unreasonable when challenged on this point. That is the meta-narrative against Sanders.

Here is why this argument isn't working. The same class of professional wonk, progressive organizer and Democratic leader who now says Sanders policies are impossible and his supporters just angry know-nothings also said that it was impossible Bernie Sanders would be competitive with Hillary Clinton in the Democratic primaries. And they were wrong.

Why should the professional progressive-Democratic consensus about the prospects for Sanders's policies be correct when the professional progressive-Democratic consensus about the prospects for his candidacy appear to have been completely wrong?

As Greg Sargent wrote this morning , the professional pundit consensus badly underestimated both Sanders and his supporters:

NBC’s Kasie Hunt has a terrific segment this morning on the surprise success of Sanders’s campaign that should be a must-watch for all Democrats. It shows a range of pundits last spring mocking Sanders’s socialism, his “thick Brooklyn accent,” his age (“he looks 91″), and his manner (“he’s a loon”). But then Hunt’s segment smartly shows footage of the roaring crowds at Sanders rallies, and the deep passion and commitment of the young volunteers putting in long hours in a Sanders Iowa campaign office, concluding: “If Bernie Sanders is going to beat Hillary Clinton in Iowa, it’s because of volunteers like these, who basically live here.”

Here is the segment in question:

Now, it was not always the same people predicting that Sanders and his supporters had no chance who are now saying his policies have no chance and his supporters are full of anger and naivete. But it was a lot of the same people, and considered as a whole it was the same type of elite consensus. That consensus was wrong before--why would it be correct now?

Sec. Clinton could still win Iowa on Monday. Doing so would, I believe, make her an extremely heavy favorite to win the nomination. So maybe this argument will prove effective after all--or at least prove to have been good enough, even if it wasn't great.

However, if Sen. Sanders wins, we might well be in for a long nomination campaign, especially since he is likely win New Hampshire as well. If that happens, as a neutral observer, I would recommend to those who favor Sec. Clinton to come up with something different than arguing that Sanders, and the policies he supports, are unrealistic and impossible. After all, by definition, something that is unrealistic and impossible shouldn't be actually happening.