In an exchange with Paul Krugman, political scientist Alan Abramowitz made one of the best cases I've heard for, as Krugman put it, "thinking the Trumpthinkable." At some point, Abramowitz argued, pundits need to admit that Trump has a good chance of winning the Republican presidential nomination.

But that remains a minority viewpoint. Nate Silver, for instance, published a piece arguing that analysts extrapolating forward from Trump's current (and impressively durable) poll lead are likely to be disappointed. So I called Abramowitz and asked him to walk me through his argument in more detail.

Ezra Klein

Right now, the betting markets have Donald Trump at about 20 percent to be the Republican nominee. Do you think that's too high or too low?

Alan Abramowitz

I think it might be a little too low. I certainly don't think he's a strong favorite, but there's no way of really coming up with an accurate prediction of these things. Forecasting nomination contests is a fool's game, I think. I saw what Nate Silver posted on FiveThirtyEight, and what he's saying is reasonable based on the history of these presidential nominations, but there are a couple things I think are different this year.

Silver makes the case that the polls at this point don't necessarily mean much, and you can get big swings in voter preferences in relatively short periods of time. And that's true. What I think is different is Republicans are tuned in to a much greater degree than they were at this point in previous nomination contests. You can see that in polling when you ask whether voters are paying attention, and you can see that in ratings for the debates. The idea that voters aren't tuned in yet and won't make up their minds till January or later may not prove as true as it has in the past.

Because of the higher level of interest and attention this year, these early polls may be more predictive of what's likely to happen.

The second point is Trump isn't only leading in national polling. He's leading in every state poll I've seen. He seems to be ahead in Iowa, in New Hampshire, in South Carolina, Nevada.

Voters say he's a strong leader who will shake up Washington, and that's what they want. He's the leader on big issues like immigration, terrorism, the economy. And the Washington Post/ABC News poll found a plurality — even more voters than actually support him — think he's the candidate with the best chance of winning in November.

If Trump does start to fade out, the good news, from the standpoint of Republican leaders and strategists, is that Ben Carson seems to be beginning to fade in support. The bad news is that the guy who is really well-positioned to pick up Carson and even Trump supporters is Ted Cruz. And Cruz right now is right on Trump's heels in Iowa. He has a very strong organization there, and it's an electorate he could do very well with.

So, to me right now, it looks like there are three potential Republican nominees, and that would be Trump, Cruz, and Rubio.

Ezra Klein

A lot of pundits — and I include myself in this group — have a sort of Underpants Gnomes theory of Marco Rubio's chances. Step one is Rubio is the only acceptable nominee to Republican elites. Step two is ... something. And step three is Rubio wins the nomination.

But when I really look at Rubio, he is about as stylistically and substantively different from Trump as you can get. Rubio is Trump’s opposite: young where Trump is old, Hispanic where Trump is white, courtly where Trump is brash, hopeful where Trump is angry, intellectual where Trump is instinctual, an insider where Trump is an outsider, soft on immigration where Trump is beyond hard-line.

That, plus the fact that Rubio's really barely moved in the polls, makes me wonder why so many pundits — again, myself included — feel he's such a likely nominee.

Alan Abramowitz

I agree. In many ways, Rubio offers a pretty sharp contrast with the three anti-establishment candidates. But if you look at his favorability numbers among Republican voters he's very well-liked, and he has very low unfavorables. He has ties to the Tea Party, he's very conservative, and so he's the only plausible establishment candidate I can see winning the nomination at this point.

Ezra Klein

You mentioned that polling shows Republican voters think Trump has the best chance to win the general election while Republican elites are terrified of nominating him. Are you sure Republican voters are wrong there? I think I could make a case that Trump is a stronger general election candidate than, say, Ted Cruz.

Alan Abramowitz

It matters less who the nominee is now than it used to. The overwhelming majority of Republican voters will vote for the Republican nominee no matter who it is, and that's true even if it's Donald Trump. The dislike of Obama and Clinton and the Democrats is so strong that I don't think you'll see mass defections.

But I think you would see some defections, and a Donald Trump would really help with the Democrats' task of mobilizing their base. The Latino vote would certainly be larger than it's ever been. There's no question Trump really scares Latinos and they despise him. There's no other Republican candidate who attracts that kind of animus from Latinos. So I don't see how he could win. I don't see one state he could carry that Mitt Romney didn't carry.

Ezra Klein

In his piece, Nate Silver basically argued that pundits were taking Trump's chances too seriously, but one thing I was thinking about after reading the article is I can't think of a candidate who has been this dominant, for this long, and has been taken less seriously by the media. We pretty much continually cover Trump as if there's no way he can win the nomination, despite the fact that he's led the polls for a long time now. Even when people do consider the idea that the guy leading the polls might also win the nomination, it's framed as this bold, counterintuitive concept.

Alan Abramowitz

Certainly in 2007, Rudy Giuliani was the frontrunner for a long time. But even he didn't dominate the polling like this—

Ezra Klein

Let me push on the Giuliani comparison you're making there. Giuliani was a popular, extremely hawkish, slightly heterodox Republican mayor who ended up getting beaten by a popular, extremely hawkish, slightly heterodox Republican senator. He didn't win, but his replacement was someone very much like him. If that's the analogy for Trump, then I don't see how the support goes to Rubio.

Alan Abramowitz

That's fair, and McCain was pretty lucky. If you look at the way the field lined up in the early primaries, he had a divided field of more conservative candidates who split the vote against him. Giuliani didn't even run in New Hampshire. And Republican voters were not as hostile to their own party's establishment.

Ezra Klein

A lot of the skepticism to Trump — and I include my skepticism here — assumes that at some point, Republican voters take the cue from Republican elites that this guy either is a bad bet in the general or ideologically untrustworthy. But I don't know how much more strongly the Republican Party, and frankly the entire media, could be sending that signal. I don't think I've ever seen such a diverse array of elected officials, party influencers, and media outlets hammer home the same point so relentlessly. So I don't know why it is that we're confident the signal will start working given its complete and total failure up till this point.

Alan Abramowitz

There have been very clear signals already from the Republican establishment, from Fox News, from conservative pundits — it's been clear they think this is really bad for the Republican Party, but it hasn't worked so far.

There have been repeated moments when Trump said something outrageous and there were predictions that this is the beginning of the end of Trump, and then he does better. This goes all the way back to his attacks on John McCain's war record and his sexist attacks on Megyn Kelly. These things don't seem to hurt him. Among his supporters, they take that as a sign that this is a guy who speaks his mind, says a lot of things they agree with — and besides which, who do you trust, Donald Trump or the mainstream media that is telling you he's lying?

Ezra Klein

It seems to me that every time Trump refuses to buckle in one of those fights with the media he proves the central idea of his campaign, which is that he won't be like those Republicans who go to Washington and then get cowed by the media and the special interests into compromising with Democrats and giving up their principles. Every time he refuses to give ground, it's proof that he won't disappoint them by giving ground in office, too.

Alan Abramowitz

I think that's exactly the way they feel, and I don't see what changes that in the next couple of months. It's hard to imagine him doing things much more outrageous than what he's already done.