Anyone who has ever ridden a roller-coaster knows the feeling.
The unsettling mix of anticipation and dread that comes after the harness is locked in place and the ride starts slowly climbing toward the sky.
You're waiting for the slow climb to switch to a terrifying descent, filled with twists and turns and flips that come at you so quickly, all you can do is scream.
In a strange way, that's pretty much where we are in U.S. politics right now.
One year out from the vote that will determine whether Donald Trump earns a second term in the White House, the campaign is about to pick up speed.
The twists and turns and noise of the 2020 campaign could feel overwhelming.
With that in mind, here are five things Canadians should pay attention to over the next 12 months as they try to make sense of what's really happening in the election south of the border.
1. Wavering senators
As the partisan theatre of the impeachment inquiry against Trump dominates the headlines over the next three months or so, pay particular attention to any Republican senators who stop defending the president, or even start speaking out against him.
The Democrats seem likely to impeach the president in the House of Representatives, but to actually remove him from office, they would need 20 Republican senators to turn against Trump in a Senate trial.
Elaine Kamarck, a senior fellow at the Brookings Institution think-tank in D.C., calls that scenario "improbable, but not impossible."
The Republican base remains very loyal to Trump — a fact that doesn't escape the president or his Republican colleagues in Congress.
Going after Trump not only carries the risk of incurring his wrath on social media, but also the wrath of his supporters at the ballot box.
So who could turn against the president?
There are five senators, including Richard Burr of North Carolina, chair of the Senate intelligence committee, who have announced they are retiring or not seeking re-election. That means they don't have to worry about the threat of a primary challenge, should they decide to vote for removal.
There's a different calculation for moderate senators running for re-election in mostly Democratic states. For example, a vote in support of the president could cost Susan Collins of Maine and Cory Gardner of Colorado the votes they need to keep their jobs.
Kamarck says most Republican senators have been keeping quiet on the Ukraine issue and will likely be watching opinion polls very closely as public hearings begin.
The first of those hearings is set for Wednesday, with U.S. diplomat Bill Taylor and State Department official George Kent, followed on Friday by former U.S. ambassador to Ukraine Marie Yovanovitch. Democratic investigators promise more to come.
Yet, we already know the story they'll tell.
That Trump wanted Ukrainian President Volodymyr Zelensky to investigate his potential 2020 opponent, former vice-president Joe Biden, as well as Biden's son, Hunter. That he also wanted Zelensky to investigate a theory about the origins of the investigation into Russian interference in the 2016 U.S. election.
And, perhaps most importantly, that the Trump White House held back military aid to Ukraine while these requests were made.
Expect many Republicans to frame this behaviour as bad — but not bad enough to warrant removing the president from office.
If that message sticks, and there are no new revelations about Trump's behaviour, veteran Republican campaign strategist Ford O'Connell predicts the impeachment process won't have a major impact on the presidential race.
"Chances are this is something that will probably be over by mid-January. And it will be another blip."
2. The chosen Democrat
It may be too early to know who will win the Democratic presidential nomination, but it's not too early to predict how Trump would target his potential rivals.
Say, for example, the Democrats choose someone from the party's left wing, promising an overhaul of government services, including providing Medicare for all and government-funded university tuition.
Sen. Bernie Sanders has admitted getting rid of private health insurance in favour of a fully public system would mean raising taxes for the middle class. And while Sen. Elizabeth Warren says she can avoid taxing the middle class to deliver a public system, critics say her recently released plan, which would feature $20.5 trillion in new government spending over a decade, is unrealistic.
O'Connell says Trump would inevitably paint such a rival as a dangerous socialist out to take Americans' hard-earned money — and it could work.
"Seventy per cent of Americans consider themselves middle class," he said. "Therefore, if they get a whiff that anybody but Scrooge McDuck is going to get taxed, that's a small problem."
We've already seen the kind of attacks Trump will launch at the moderate front-runner, former vice-president Joe Biden.
The accusations that Biden's son Hunter was up to no good with his business dealings in Ukraine remain unfounded, yet they have put the Biden campaign on the defensive, with both the candidate and his son going on network TV to defend their actions and condemn the president's attacks.
And the president's current nickname for Biden — Sleepy Joe — echoes the way Trump characterized the one-time Republican front-runner in the 2016 race, former Florida governor Jeb "low energy" Bush.
Silly though it may be, it stuck.
"That's all the guy knows how to do, is run a nasty race," said Kamarck.
While Biden, Warren and Sanders are currently the front-runners, the dark horse candidates have vulnerabilities, too.
Take Pete Buttigieg, the mayor of South Bend, Ind.
At a rally in Greenville, N.C., back in July, Trump discussed the fact that black residents in South Bend have been very critical of Buttigieg's leadership.
Buttigieg's overall lack of support among black voters is a major weakness of the 37-year-old's campaign, and the president knows how to hit where it hurts.
"If that's a hot young star, I guess I just don't know stardom anymore," Trump told the crowd.
3. The handful of states that could decide everything
The deep political polarization in the U.S. means the 2020 election will likely be decided by a relatively small number of persuadable voters in a few swing states.
Kamarck says the only way Trump will be re-elected is if he can once again pull off wins in Michigan, Wisconsin and Pennsylvania, putting him over the edge in the electoral college.
"The whole ball game's there."
She points out that Democrats did well in each of those states in the 2018 midterm elections, which is a bad sign for Trump.
Florida, which went for the Republicans in 2016, could also be in play. The Trump campaign has also targeted Minnesota, which narrowly went to the Democrats that year.
If you want to know how the Trump campaign is doing, check out where he holds his made-for-TV rallies.
If Trump's Keep America Great show stays focused on Pennsylvania and Florida, the race is close. It shows he is trying to solidify his base of support.
If he starts speaking to more crowds in places like New Hampshire and New Mexico, that's a sign his campaign is confident and looking to stretch its lead.
4. War in the digital world
One of the biggest challenges facing the Democratic nominee, whoever that is, will be figuring out how to compete with the president in the message battle online.
In a four-week period beginning at the end of September, the Trump campaign spent $7.3 million on Facebook and Google ads. That's more than top Democratic candidates Elizabeth Warren, Joe Biden, Bernie Sanders and Pete Buttigieg combined.
Republicans have a growing pile of cash. The party broke fundraising records in the quarter ending Oct. 1, taking in $125 million.
Democratic fundraising is split among the many contenders for the nomination, each of whom uses their money to compete against each other. Sanders led the latest quarter with $25.3 million in donations.
In 2016, the Trump campaign was particularly skilled at microtargeting voters with messages that tapped into their emotions, especially their fears over divisive topics such as immigration.
So, how will the Democrats fight back?
A progressive non-profit group called Acronym, along with an affiliated political action committee, plan to counter Trump's digital advantage with a $75-million campaign featuring targeted advertising in key states.
Describing the challenge ahead, Acronym founder and CEO Tara McGowan told the New York Times that Trump has upped the ante by spending more than any candidate ever has this early in a general election campaign.
"And right now, our side is simply not on the field," she said.
Still, there's no guarantee the digital strength of Trump's campaign will translate into as many votes this time around, Kamarck said.
"We don't know if his massive expenditures are doing anything more than riling up his base," she said.
"And his base, at this point, is not big enough to win again."
5. The health of the economy
One of the most important factors to watch over the next 12 months is the economy.
A year out from the vote, three economic forecasters — Moody's Analytics Inc., Prof. Ray Fair of Yale University and Oxford Economics — all predict a Trump victory in 2020.
Unemployment is at record lows, growth is up, and inflation appears to be in check.
And even though Trump's trade wars have hurt certain sectors of the economy, such as manufacturing and farming, American consumers have kept spending.
It's no wonder Trump starts every rally by touting his economic accomplishments.
But those models are based on how elections have played out historically and may not take into account factors unique to the Trump presidency.
They don't consider, for example, scandals associated with the president or some of his specific policies. After all the volatility associated with Trump's trade wars, particularly with China, it's unclear how many voters will give the president credit for the positive numbers.
Democrats will certainly go out of their way to argue this is Barack Obama's economy — and Trump just happens to be around to take credit for it.
And then there's the chance the economy could take a turn for the worse.
"We may have a recession by next year. Absolutely could happen. And if that happens, it's the end of Trump. He is not going to be reelected," Washington Post columnist Megan McArdle recently told The National's Adrienne Arsenault.
How likely is that?
Bloomberg's recession tracker places the odds of a recession in the next year at 27 per cent, explaining that "there are reasons to keep a close eye on the economy, but it's not time to panic yet."
Don't spend too much time on it; it'll make you crazy - Elaine Kamarck, Brookings Institution
So, to recap, we're not exactly sure what will happen with the economy. We do know the digital advertising game is Trump's to lose and that his attacks are going to be nasty. But we also know the impeachment fight could change the entire race — or nothing at all.
It's enough to make your stomach flip.
But unlike a roller-coaster, Canadians can step off this ride and catch their breath every now and then.
Kamarck recommends taking breaks from the drama.
"Don't spend too much time on it; it'll make you crazy," she said.
And there's one more thing to remember about roller-coasters: No matter how intense the ride, it all goes by in a flash.