This continues to be one of the more unexpected charts of the 2016 primary, so far.

It shows the distance between the leading and No. 2 candidates in Real Clear Politics's average of national polls since June 1. Once upon a time, it seemed like the Democratic line would always be well above the Republican one. But with Hillary Rodham Clinton's slide and Donald Trump's ascent, that's not the case.

A new national poll from CNN/ORC shows just how different the Democratic race is than might once have been expected. Now we have, weirdly, a three-way race -- at least according to this one poll -- as Clinton continues to slip and Joe Biden starts to gain. Joe Biden!

I'm old enough to remember when this was a Clinton-Bernie Sanders contest! Well, that picture has gotten more complex, too. Sanders actually lost ground between CNN's two most recent polls.

Clinton's still up by a decent margin, of course. But -- and make sure you're sitting down for this -- her lead is 10 points, slightly less than Donald Trump's lead in CNN's recent national survey of Republicans. She's up 10; he's up 13 -- and he's running against slightly more opponents who carve up the vote and make building a massive lead more difficult.

In some ways, though, this poll is almost as bad for Sanders. When you add in people's second choices, he drops to third behind Biden. Sanders is counting on momentum; as we noted Thursday, he continues to stay flat nationally.

Democrats also still feel as though Clinton will win -- and feel more comfortable with her as the nominee than either of the other two contenders.

I guess we should at this point note that Biden isn't even a candidate. Once/if he gets in, the picture should change a lot -- and if he doesn't, it continues to look like Clinton will be the beneficiary.

Diving into the poll a bit, we can see where Clinton, Sanders and Biden lost and gained support since the last poll. There are big margins of error on these (indicated with the gray bars) but they're still worth looking at.

An important point on the following graphs: "Someone else" doesn't refer to Martin O'Malley, Jim Webb or Lincoln Chafee -- it's people who told the pollster "someone else" after hearing all of the names of Democratic candidates. In other words, it's "none of the above." So notice that the percentage of men saying they wanted to vote for none of the above increased by nearly 10 points -- as their support for Clinton sank.

Also notice the big gains for Biden with women and that Clinton's numbers with liberals are plummeting -- as Sanders's numbers with moderates and independents fell a lot, too.

This is a mixed-up, scrappy field right now, with a maybe-candidate surging and the establishment favorite floundering. It looks little like what many would have expected the race to look like at this point.

And, again: Clinton's lead is smaller than Donald Trump's. Clinton's lead is smaller than Donald Trump's. Here. In this universe.

What else can you say?