Here are the names, numbers and next steps our panel of top political reporters will be watching for in the year ahead, in this week's "Inside Politics" forecast.
1. Pelosi & McConnell
A big relationship to watch on Capitol Hill this year: the one between Senate Majority Leader Mitch McConnell and incoming Speaker of the House Nancy Pelosi.
"They're two veteran legislators, they're pragmatic when they need to be, they have an innate sense for their members and the ability to count votes. And that's about where the comparisons end," reports CNN's Phil Mattingly.
"They're not friendly. They don't hang out. The only time they're in the same room together is because there's a big deadline or someone being honored," Mattingly said. "These are going to be two people who have to strike deals to keep the government open, extend the debt limit. There's not going to be a ton of policy that gets done in the next two years, but those crucial deadlines are going to come down to those two leaders, their relationship, and how it grows or doesn't grow."
2. Sen. Mitt Romney
Will anyone replace Sens. John McCain, Jeff Flake, or Bob Corker as Republicans willing to speak truth to power to this White House?
"In the last Congress, McCain famously broke with Trump on health care and on foreign policy. Flake often expressed his concern over Trump's tone, and Corker derisively dubbed Trump's White House an 'adult day care center,'" CNN's Nia-Malika Henderson said.
But McCain passed away this year and Flake and Corker are retiring.
"So what about the incoming caucus? One obvious name that keeps coming up among Republicans is Utah's new senator Mitt Romney, who was one of Trump's harshest critics in 2016," Henderson said. "Of course, he also considered joining Trump's administration and during his Senate bid said he was more hawkish than Trump on immigration."
"So who will Mitt Romney be in the Senate? And if he takes up even a small part of the McCain/Flake/Corker mantle, will he have much company? That's one of the questions floating around Washington, particularly among establishment GOPers."
3. The Trump Economy
The state of the economy could be the biggest factor in determining whether President Trump wins re-election. And after a tumultuous month on Wall Street, the White House is worried, The Washington Post's Josh Dawsey reports.
"The stock market's been pretty volatile, and some indicators are not looking as good," Dawsey said. "This is a president who watches the stock market every day, who's obsessed with these economic metrics because he sees them as posing an existential threat to his presidency if they go down," Dawsey said.
And the President's trade war with China is behind a lot of the volatility.
"A lot of whether that can turn around or whether that can stay positive for the president hinges on China," Dawsey said. "So I think for the trade agenda, which is obviously one of his biggest priorities, we're going to be closely watching whether any sort of deal can be struck.
4. A second North Korea summit?
Despite signs that North Korea isn't honoring promises made at the Singapore summit, President Trump says he wants to meet with Kim Jong Un again early in 2019.
"It was about six months ago that they famously shook hands in Singapore, which got huge attention but only yielded a vaguely-worded commitment to a nuclear-free Korean Peninsula, and there's been sort of limited progress on that so far," the AP's Catherine Lucey said.
"I think whatever we see out of a potential meeting, one thing you can be sure of is that the president is going to treat this with similar fanfare as he did the first time around -- a lot of drama, a lot of showmanship. He is already trying to build excitement and suspense."