Hillary Clinton Hillary Clinton (Susan Walsh/Associated Press)

Nate Silver:

From the standpoint of the party primary, it’s almost as though she’s an incumbent president, right, where she even trumps, kind of, the VP, who very often wins nomination after a president is term-limited. If you look at polls, you know, 60 to 70 percent of Democrats say they prefer Hillary to be the nominee. There’s no kind of non-incumbent in history with those types of numbers.

Here’s the problem. We have no precedent for a potential nominee, outside of incumbents, seeming to be as strong as Hillary Clinton right now — at least in the opinion polls. But because it’s unprecedented, there’s really no way to know what it means. Is her overwhelming lead hard or soft? We don’t know, and won’t until she’s attacked by a Democrat or stumbles on her own, and it may be a long time before either happens. Is it enough to chase other candidates out? We don’t know that one, either, yet. Does it reflect widespread agreement among party actors that Clinton should be nominated? We don’t know — and we can’t know, because as long as her polling holds up and it’s unclear what her eventual intentions are, there’s no reason for anyone out there to say anything negative.

That’s not to say that Clinton is a weak candidate. At the very least, she the kind of first-tier candidate who usually runs strong, and usually wins. But whether she’s more than that is just impossible to know at this point. She could well be an Al Gore type who wins in a walkover against a bit of token opposition — but she could just as easily be more similar to Walter Mondale in 1984, George H.W. Bush in 1988, Bob Dole in 1996 … and Hillary Clinton in 2008. And my guess is that we’re a long way from finding out.