Donald Trump rewrote the rules of presidential politics in 2015, vaulting to front-runner status in the GOP race without any significant TV ad spending, and far less old-school retail politics than his rivals.
And now that the voting is just around the corner -- Iowa goes first in 35 days -- CNN's Sara Murray says that's not likely to change much.
Trump, she reports, will visit Iowa and New Hampshire in the days ahead but keep to his 2015 plan of also visiting states far later in the nominating calendar.
"This is a smart strategy in that it does not pin him down to a must-win state," said Murray. "But if you're one of these voters in Iowa and New Hampshire, guys that like retail stops and like the bus tours, Donald Trump isn't doing that."
2. The dog that didn't bark in 2015: Super PACs
As 2015 began, there was lots of talk about a supposed new rule in politics: Get a deep-pocketed friend or two to launch a super PAC on your behalf, and things will be easier as a candidate.
But Dan Balz of The Washington Post noted that as the year winds down, there is little evidence the millions spent by super PACs have had much influence on the race.
"They spent tens and tens of millions of dollars to no effect, and it's hurt the candidates that the super PACs have been spending on," said Balz. "We'll have one more test starting early next year, as we get closer to Iowa and New Hampshire, as the super PACs unload what they've got."
3. Enjoy the holidays, Mr. Speaker -- the honeymoon may be ending
Not all of the big Republican political news happened on the presidential trail in 2015. Paul Ryan became the new House speaker, and early on managed to avoid tea party battles and other restless conservatives that were the norm during John Boehner's tenure.
But the Ryan honeymoon may not carry over to 2016, The New Yorker's Ryan Lizza told us, because the more that conservatives learn about the giant year-end spending bill passed by the Congress, the less they like it.
"All the conservatives are saying if Paul Ryan does not deliver some victories early in 2016, he's going to start to face the same dynamic that John Boehner faced during his short-lived reign as speaker," said Lizza.
"Raul Labrador, the founder of the Freedom Caucus, said, 'The honeymoon is over.'"
4. Some big names are still on the sidelines: Will they endorse?
Early-state endorsements are historically a big help in presidential politics, and there are some big names still officially on the sidelines as 2015 gives way to 2016.
Some senators in early-voting states -- Joni Ernst of Iowa, Kelly Ayotte of New Hampshire, Tim Scott and former presidential candidate Lindsey Graham, both of South Carolina -- have not endorsed a candidate. Nor has South Carolina Gov. Nikki Haley.
Some of them may choose to stay on the sidelines, but they will be lobbied right up until the voting -- and CNN's MJ Lee says they have the chance to influence the early contests.
"If anyone is in a position to pick up a majority, it's probably Marco Rubio," said Lee. "Tim Scott has done everything but endorse Marco Rubio. So maybe Tim Scott will be the first domino to fall."
5. A busy New Hampshire week ahead tells you things are wide open in the Granite State
The final week of the year is usually relatively quiet in New Hampshire, even when the presidential primary looms just weeks away. Candidates tend to focus on end-of-the-year fund-raising, or downtime, or maybe a trip to Iowa because it votes first.
But nearly all the GOP contenders are scheduled to hit the Granite State at least once this week -- and that speaks volumes about how the campaigns view the state of the GOP race.
The consensus among most top Republicans is that Iowa looks more and more like a Ted Cruz state. And if that happens, one big question is this: Will Donald Trump's consistent New Hampshire lead hold or collapse if his "winning" brand is called into question?
That is one reason New Hampshire is getting even more attention than usual. Also, New Hampshire could decide if there will be a strong establishment candidate early in the process, or whether the contest begins as more of a Trump-Cruz battle.
Chris Christie, John Kasich, Jeb Bush and Marco Rubio all view New Hampshire as a defining test -- though their campaigns are careful not to say winning is a necessity.
For Team Rubio, the year-end buzz has been strong, and CNN is told the senator from Florida will report a strong fourth-quarter fund-raising total. But you need to win states to win the nomination, and at the moment Rubio isn't leading anywhere. But Rubio insiders insist there is enough money in the bank to soldier on into March.
And take this as you wish: Two GOP strategists working for other candidates say it is premature to count out Jeb Bush in New Hampshire.
Those veterans suggest the race there is likely to have a reshuffling as the calendar turns to 2016, and the voters get more serious about the primary.