This gentleman had a good year. (Charles Ommanney/The Washington Post)

One year ago Thursday, which is to say on Dec. 31, 2014, Jeb Bush was preparing to shock-and-awe his way to the Republican presidential nomination. There weren't a lot of polls in the bank at that point, but in the ones that there were, Bush led. His national average (in Real Clear Politics's estimation) was 17 percent -- good enough for a 5.8-point lead over the guy in second. Who was Chris Christie. Not making this up. Christie was just ahead of ... can you guess?

Randal Howard Paul.

No one was even polling on Donald Trump, because obviously Donald Trump wasn't actually going to actually run. He was no Scott Walker, a serious candidate who was at that point tied for fourth place.

Imagine if, 365 days ago, I'd presented you with the current standings in this thing. "Yes," I'd explain. "That Trump." And, yes, I'd nod, Jeb Bush is indeed in sixth place. What a world!

2015 has been very, very bad for Jeb Bush and, of course, very, very good for Donald Trump. We can look at the change in the Real Clear Politics average for each candidate nationally and in Iowa and New Hampshire to see that plainly.

Trump -- and on the Democratic side, Bernie Sanders -- saw the biggest gains over 2015, with Ted Cruz just edging out Trump for the best improvement in Iowa. Hillary Clinton saw the biggest erosion of her support on the Dem side, with Bush dropping the most nationally for the Republicans. Looking at early-voting states, Mike Huckabee and Rand Paul saw the biggest dips in Iowa and New Hampshire, respectively.

Here's a related bit of data: Trump and Sanders also saw their parties' biggest gains in net favorability (both among members of their party and overall), while Clinton and Bush saw the biggest drops.

That's all well and good, but we wouldn't be doing our jobs if we didn't dive way deeper. So we tracked each candidate's numbers over the past 12 months and now present them for your enjoyment. See below, with a bit of analysis, and then remember to take an extra gulp of champagne on Jeb Bush's behalf as the clock strikes midnight. He's having a much worse New Year's Eve than he did last year.

The Republicans

How these graphs work: The wide graph at left tracks polling average for the candidate over the past 12 months (or as far back as there is data). The middle graph shows the full range of the candidate in those polls over 2015, with their current position marked. The graph on the right shows the change in net favorability.

Jeb Bush's last name means we get to wring our hands over him first. But what do we say? That middle graph shows that he's at the bottom of this range over the course of 2015. A tiny uptick in New Hampshire recently? Happy new year, Jeb, you have a tiny uptick in New Hampshire after a long tumble down a steep hill.

Ben Carson's past few months have been just about as rough. He's headed back down to levels of support that he had before his big autumnal surge, without even a small uptick to make things slightly better.

Chris Christie, however, finally has some good news. He slipped over the course of the year, but his numbers in New Hampshire have nearly recovered to the highs he saw at the beginning of 2015.

You know who had a good 2015? Ted Cruz did. He offers a good contrast with Christie (and other moderates, as you'll see) in that he's gained a lot in Iowa while not moving much in New Hampshire. Few candidates saw big gains in both states, save the classiest one. Cruz is spiking at a very good time, of course.

Carly Fiorina's 2015 looks like a car with a bad motor. You keep thinking it's going to catch, you hear it grind and sputter -- but then it doesn't. Two good debates helped her. For a bit.

The favorability numbers for Mike Huckabee are pretty grim, mirroring his deep slide in the polls. At the end of 2014, Huckabee had a nearly 2-to-1 lead in Iowa, the state he won in 2008. Now he's tied for 10th.

John Kasich is one of those good-in-one-state-bad-in-the-other guys. He's off his highs in New Hampshire, but he's still doing decently. His milquetoast favorability ratings may be mostly a function of a lot of people still not knowing who he is.

Rand Paul had a bad 2015. His plummeting favorability almost certainly explains his crumpling poll numbers, which did hold fairly steady -- until the rise of Trump.

Marco Rubio did something pretty remarkable for 2015: He recovered. He was doing decently in the beginning of the year  and then sank as anti-establishment candidates roared ahead. But he slowly rebuilt his position, thanks in part to strong debate performances. Slow and steady may be too slow at this point, but he seems steadily headed in the right direction.

Started low; only went down.

Remember this guy? One year from now, I am going to write an article similar to this and I am going to use this graph and I am going to say, this was a real graph from December 2015, believe it or not. And you will look at it and you will think, What a time. What a world.

The one thing to note here is that Donald Trump is near his peaks nationally and in Iowa, where he trails Ted Cruz -- but is slipping in New Hampshire.

The Democrats

Hillary Clinton had a largely lousy autumn: Until Joe Biden dropped out in late October, she was leading a three-person race by a small margin. Once Biden left -- providing her the rocket booster we predicted -- she regained a substantial (but smaller) lead.

Martin O'Malley's actually doing better! In the sense of that guy in "Monty Python and the Holy Grail" who is being carried out to the cart of corpses and insists that he wants to go for a walk. Coming soon: a loud "thunk."

It is fitting to begin with Jeb Bush's collapse and end with Bernie Sanders's ascent. There it is, one of the two best 2015s of all of the 2016 candidates. Big gains in favorability, mostly as a function of people getting to know him. Support climbing steadily until a recent plateau. The sort of graph that any of the Republicans would be thrilled to have -- and the sort of graph that almost certainly won't make Bernie Sanders the next Democratic presidential nominee.