Image source, Getty Images

The impeachment inquiry may have exacerbated deep divisions in the US, but Donald Trump has been a polarising figure since he first announced he was running for president.

And perhaps nothing illustrates the love-hate divide better than the Make America Great Again baseball cap he donned on the campaign trail.

For the BBC's Cut Through The Noise, external show, we travelled across the US to ask Americans what the MAGA hat means to them.

"I wear this hat to represent my country, and I'm proud to be an American," one woman outside a Trump rally in Wisconsin told us.

But another woman at a store in Minnesota argued: "It represents nationalism, xenophobia and a 1950s America."

How did a red hat come to mean so much? Watch the full show below.

Vice President Mike Pence had time to get into the Christmas spirit in Michigan ahead of tonight's rally.

He tweeted: "We are making Christmas great again!"

He earlier tweeted:

Throughout the day, Pence has also retweeted posts calling the impeachment process "rigged", "politically biased" and a "reckless use of power".

The temperatures may be well below zero outside the Kellogg Arena in Battle Creek, Michigan, where Donald Trump is due to speak this evening.

But that's not stopped his fans - and his critics - from gathering in their droves.

They had different ways of keeping warm, from wrapping themselves in blankets... to wearing a gigantic papier mache Trump head.

Image source, Getty Images

Image source, Getty Images

One woman told local newspaper the Battle Creek Enquirer, external that she started queuing up for her 31st Trump rally two days ago.

Saundra Kiczenski said rallies were more exciting than concerts.

"I've been to well over 250 concerts, and those aren't super exciting from start to finish because there's always downtime... but here, you're hearing firsthand all the real news of what's happening in the country."

Texas Republican Louis Gohmert alleges that impeachment is intended to "stop the investigation by the US Department of Justice and Ukraine into the corruption of Ukraine's interference in elections in 2016."

There is no evidence that Ukraine tried to meddle in the 2016 election. According to the US spy community, Russia tried to meddle in the US election, although Trump and other Republicans have cast doubt on that.

After Gohmert speaks, Democrat Jerry Nadler responds: "I’m deeply concerned that any member of the House would spew Russian propaganda on the floor of the House."

Gohmert then refuses to leave the floor, shouting out to Nadler that he must rescind his comments.

Image source, Reuters

Trump's spokeswoman has said that the president is only occasionally tuning in to today's impeachment debate, but we know of one broadcast he is definitely watching.

Earlier Trump tweeted praise of Fox & Friends, his favourite TV programme, indicating that he was watching and appreciated the coverage.

"Well said Brian," he tweeted to host Brian Kilmeade after the host described Trump's impeachment as "trivial".

Part of the three-hour show today was devoted to a look back at the year, and featured a montage of presenter Ainsley Earhardt dancing.

During today's historic vote, Fox News also aired a segment showing Brian Kilmeade going "home for the holidays" and bringing his two fluffy pooches to meet Father Christmas.

We are still several hours away from the all-important vote.

So it seems as good a time as any to catch up on how exactly we got to the point where President Donald Trump could be impeached.

Watch our video above, by BBC journalists Tristan Cimini and Shrai Popat, for a three-minute overview.

At least two senators - Democrats - say they have received Christmas cards from the White House today with an extra unexpected gift.

Tucked inside was a copy of Trump's blistering six-page letter to House Speaker Nancy Pelosi setting out why he should not be impeached.

Part Twitter rant, part legalise, the letter rails against Democrats saying that they are "offending the Founding Fathers".

"It is time for you and the highly partisan Democrats in Congress to immediately cease this impeachment fantasy and get back to work for the American People," the president wrote late on Tuesday.

"While I have no expectation that you will do so, I write this letter to you for the purpose of history and to put my thoughts on a permanent and indelible record."

Read the letter, external

Trump's blistering letter to Pelosi: Five key quotes

Image source, BRENDAN SMIALOWSKI/AFP via Getty Images

The majority of Americans, 57%, now think that Trump committed an impeachable offense while 54% believe that there's enough to evidence to make the case, according to FiveThirtyEight, a statistics-driven news website.

But this doesn't mean they actually want him impeached. According to FiveThirtyEight, Americans remain locked in dead heat on this question: 47% support Trump's impeachment while 47% oppose.

Many of those who believe Trump committed wrongdoing think his fate should be determined at the ballot box in 2020 - not in an impeachment trial.

FiveThirtyEight, external 

Journalists on Twitter have noticed that one quote seems to keep coming up: Founding Father Ben Franklin's saying that America will be a democracy "if we can keep it".

We asked Anthony for a few more...

"In wine there is wisdom, in beer there is Freedom, in water there is bacteria"

"We are all born ignorant, but one must work hard to remain stupid"

"Three may keep a secret, if two of them are dead"

Trump campaign spokesman Tim Murtaugh has just shared this video of Trump supporters waiting in line to hear him speak tonight in Battle Creek, Michigan.

Battle Creek gets its name from a skirmish that took place 175 years ago between two Native Americans and government land surveyors, according to the city's website.

The event is due to start in about four hours, around the same time we could get those much anticipated votes in Washington.

Supporters are standing outside in the cold right now, in temperatures dropping to 17F (-8C).

Image source, Getty Images

"I rise today in support of impeachment," says Congresswoman Rashida Tlaib.

The Michigan Democrat has clashed with Trump since her first day in office, when she rode a Democratic mid-term election wave that took control of the House.

Only hours after she was sworn in as a lawmaker in January 2019, she drew condemnation from Republicans when she used a profanity to call for Trump's impeachment.

Speaker of the House Nancy Pelosi shrugged off the epithet at the time, saying that Trump has said worse.

Congresswoman's Trump profanity sparks furore

Pennsylvania Congressman Mike Kelly, a Republican, raises other notable events that have happened in December such as the Boston Tea Party and the Pearl Harbor WW2 attack by the Japanese, in which 2,400 Americans were killed.

"On 7 December 1941 a horrific act happened in the United States and President Roosevelt said 'this is a date that will live in infamy'."

"Today 18 December 2019, is another date that will live in infamy," he added.

He accused Democrats of being blinded by hate.

Image source, Getty Images

Photos aren't allowed inside the House - so what's going on outside?

Image source, Win McNamee/Getty Images

Image source, OLIVIER DOULIERY/AFP via Getty Images

Image source, Drew Angerer/Getty Images

Image source, Mark Wilson/Getty Images

Image source, Win McNamee/Getty Images

Anthony Zurcher
BBC North America reporter

Our North America reporter Anthony Zurcher answers some of your most pressing concerns.

What would the impact be on Trump's 2020 presidential bid if he was successfully impeached based on actions during his first term? - Grit Tokley, 29, London

That is the million-dollar question - and it's not clear what the answer is.

Republicans tout how impeachment has been a fundraising boon for Trump's presidential campaign, as his supporters rally around their embattled president. Democrats counter that this vote will be a black mark on the president's name that voters will find impossible to ignore when casting their ballots.

Polls show a sharply divided nation whose opinions about the president, for and against, have not changed much because of the ongoing impeachment drama. It is probably safe to say the 2020 election was going to be close before impeachment - and it will be close after.

Image source, Getty Images

If the Senate are (almost certainly) not going to vote to impeach Trump, then what is the point in this whole process? - Will Fox, 22, Leeds

If you listen to Democrats, the reason they're going through with this even though the outlook is slim to none for Senate conviction is because they feel obligated to hold the president accountable for his actions.

They view the president as having abused his power by pressuring Ukraine to open investigations into a political rival, and if they don't draw the line here - even if it doesn't result in his removal - the president will be emboldened to take further actions that could adversely affect Democrats in the 2020 election.

Then there's the purely political fact that the Democratic base have been howling for impeachment for months. If Democratic officeholders hadn't taken action, they would have risked the ire of their most loyal supporters - and either faced primary challenges or lost general elections because their side didn't feel sufficiently motivated to turn out at the polls.

Read Anthony's full analysis here.

"Democrats are terrified that president Trump will win re-election," says Guy Reschenthaler, a Republican from Pennsylvania.

"This is nothing more than political hit job," he says, intended to take out Trump in 2020.

"I would prosecute Adam Schiff for abuse of power," adds the former judge, complaining that the Democratic House Intelligence Committee chairman did not force an anonymous whistleblower to testify, as Republicans wanted.

"I hear a lot of attacks on Democratic members of Congress, but not one single word of substantive defense of the president's conduct," responds top Democrat Jerry Nadler.

Doug Collins, a top Republican in the House, says sarcastically that the Republicans microphones must not be working so he reiterates his side's talking points.

We're expecting each side to go one like this for about four more hours.

Earlier we mentioned the flurry of tweets from Donald Trump today.

Now, it's been reported that his press secretary says he's busy working all day - but is being kept up to date by aides.

Trump, who flies to Michigan later for an evening rally, was not going to be following every step of the proceedings as his political future is debated, said Stephanie Grisham.

She told the Washington Examiner, external: "The President will be working all day.

"He will be briefed by staff throughout that day and could catch some of the proceedings between meetings."

Here's a snapshot of how big US media is covering today's vote.

Image source, Washington Post

Image source, USA Today

Image source, Fox News

Image source, New York Times

Image source, Wall Street Journal

Republican Congressman Barry Loudermilk of Georgia noted the proximity of this vote to the Christmas holiday. He condemned Democrats for not unveiling the name of the whistleblower who first sounded the alarm about Trump's Ukraine phone call.

"When Jesus was falsely accused of treason, Pontius Pilate gave Jesus the opportunity to face his accuser," he said.

"During that sham trial, Pontius Pilate afforded more rights to Jesus than Democrats have afforded this president and this process."

He's not the only one making a Christmas metaphor.

Earlier on Wednesday, one of the top national Twitter trends in the US was "#MerryImpeachmas".

Image source, Reuters

Impeachment is a topic that Trump was talking about way before he himself took office.

Back in 2014, he discussed the possible impeachment of Barack Obama - first on Twitter, by suggesting such a move for Obama's "gross incompetence".

In a TV interview on a similar subject later that year, he said that such a move would be a "horror show" for Obama, were he to be impeached.

Some years earlier, Trump had also suggested that Nancy Pelosi should impeach George W Bush.

He told CNN in 2008, external that Bush should be impeached for his role in the Iraq war, saying: "It just seemed like she was really going to look to impeach Bush and get him out of office. Which personally I think would have been a wonderful thing."

In that interview, he also discussed Bill Clinton's impeachment over the Monica Lewinsky investigation, saying the former president had got into trouble "with something that was totally unimportant... and they tried to impeach him, which was nonsense".

Impeachment has caused the divide between parties to deepen, but while Americans too are divided on these proceedings, there are other issues that are bringing the nation together.

• Nearly 70% of Americans say the government needs to reduce healthcare costs, according to the Pew Research Center, external
• While the abortion debate is still an issue, Pew found 70% of Americans do not support completely overturning the Supreme Court decision that legalised abortion nationwide
• Another Pew poll found 73% of Americans believe big corporations have "too much power"

• A NPR/PBS poll, external found 89% of Americans overall support increasing mental health funding to help curb gun violence and 83% are in favour of more background checks, though there are large divisions when it comes to stricter gun laws

And according to Politico, external, the subject Americans were least polarised on last year? Domestic beer, with Coors being the beverage of choice for both parties.