Telltale sign that Trump is worried
After two-and-a-half years of speculation, sound and fury, the Democrats have finally announced they are starting "an official impeachment inquiry" into Donald Trump.
The catalyst is the allegation that Mr Trump misused his power as President to pressure a foreign country, Ukraine, into investigating the son of Joe Biden, his most likely opponent in next year's election.
"Today I'm announcing the House of Representatives is moving forward with an official impeachment inquiry," House Speaker Nancy Pelosi, the Democrats' leader in Congress, said this morning.
"I'm directing our six committees to proceed with their investigations under that umbrella.
"The President must be held accountable."
So what happens next? Is Mr Trump actually going to be turfed from office?
Let's run through this thing step by step.
STEP ONE: CONSOLIDATION
You will have noted that Ms Pelosi referred to six committees. She was talking about congressional committees under the Democrats' control, each of which is already investigating Mr Trump.
Some of them are examining whether he obstructed justice, as implied by the Mueller report, which was released back in April. One is trying to get its hands on the President's tax returns. Another has delved into Mr Trump's hush money payments to Stormy Daniels. There has even been some stubborn pursuit of the otherwise dormant Russian collusion thread.
The point is, these six committees have all kind of been doing their own thing, without any clear, unified mission.
Ms Pelosi is giving them that singular purpose now by bringing them under the "umbrella" of a broader impeachment inquiry.
Any information the committees dig up could be used to draft articles of impeachment against Mr Trump.
STEP TWO: INFORMATION
We are poised to learn more about the core allegation against Mr Trump - his apparent pressuring of Ukrainian President Volodymyr Zelensky - as soon as tomorrow.
The President says he has authorised the release of a "complete, fully declassified and unredacted" transcript of his phone call with Mr Zelensky.
The Wall Street Journal reports Mr Trump pushed Mr Zelensky to investigate Mr Biden's son Hunter eight times during that conversation. It will be interesting to see whether or not the transcript confirms that.
....You will see it was a very friendly and totally appropriate call. No pressure and, unlike Joe Biden and his son, NO quid pro quo! This is nothing more than a continuation of the Greatest and most Destructive Witch Hunt of all time!— Donald J. Trump (@realDonaldTrump) September 24, 2019
Separately, a member of the intelligence community who filed a whistleblower complaint about a conversation (or multiple conversations) Mr Trump had with Mr Zelensky, has indicated he or she wants to testify before Congress.
That testimony could potentially happen this week.
And after resisting pressure from Democrats, Mr Trump today agreed to release the whistleblower's official complaint.
It should soon become clear whether the whiff of scandal swirling around this story is overblown, or really is as serious as it seems.
STEP THREE: NUMBERS, NUMBERS, NUMBERS
Say the Democrats conclude there is enough evidence to warrant impeachment.
The House Judiciary Committee would then draft and approve articles of impeachment, to be voted on by the House of Representatives.
Ms Pelosi would need to find a simple majority of 218 votes - a task which isn't as easy as it sounds. The Democrats control the numbers in the House, but at the moment, fewer than 200 of them actually support the impeachment inquiry. More would have to come on board.
OK. Say they do, and the House does pass articles of impeachment. That is when the hard part starts.
RELATED: How the impeachment process works
The next step would be for the other chamber of Congress, the Senate, to hold an impeachment trial, presided over by Supreme Court Chief Justice John Roberts.
To remove Mr Trump from office, a two-thirds majority of the Senate would need to vote to convict him.
The Republicans currently control the Senate, with 53 votes to the Democrats' 47. That means at least 20 senators from Mr Trump's own party would be required to vote against him.
It doesn't seem likely.
IS TRUMP ACTUALLY WORRIED?
The President's willingness to release the transcript of his call with Mr Zelensky, along with the whistleblower's official complaint, suggest he believes the full story will vindicate him.
But eventually, that information would have emerged anyway - and there are signs he is genuinely worried.
One of those signs was the late night Twitter spree he embarked on after Ms Pelosi's impeachment announcement.
More significantly, MSNBC reports Mr Trump called Ms Pelosi before her statement to the cameras and tried to convince her to drop it.
"The President actually said to Nancy Pelosi, 'Hey, can we do something about this whistleblower complaint? Can we work something out?'" said reporter Heidi Przybyla, having seen a readout of the call.
"And she said, 'Yes, you can tell your people to obey the law.' So she quickly swatted that down and made it clear that it is full steam ahead."
The one person, perhaps, with even more reason to worry than Mr Trump himself is the President's personal lawyer Rudy Giuliani, whose own murky interactions with Ukraine have come under intense scrutiny.
Mr Giuliani suffered something of a meltdown last week when he went on CNN to address the Ukraine story. First he denied pressuring Ukraine, in his capacity as Mr Trump's lawyer, to investigate the Bidens. Then, literally seconds later, he contradicted himself.
"Did you ask Ukraine to investigate Joe Biden?" host Chris Cuomo asked.
"No, actually I didn't. I asked Ukraine to investigate the allegations that there was interference in the election of 2016 by the Ukrainians for the benefit of Hillary Clinton," Mr Giuliani said.
"You never asked anything about Hunter Biden? You never asked anything about Joe Biden to the prosecutor?" Cuomo pressed.
"The only thing I asked was to get to the bottom of how it was that the guy who was appointed dismissed the case against Antac (a company Hunter Biden was associated with)," Mr Giuliani replied.
"So you did ask Ukraine to look into Joe Biden!" Cuomo pointed out.
"Of course I did!" Mr Giuliani said.
"You just said you didn't!" said Cuomo.
Mr Giuliani made an even wilder TV appearance on Fox News today. He clashed with Democrat Chris Hahn, who accused him of "making things up" about the Bidens.
"Shut up, moron! Shut up! Shut up! You don't know what you're talking about. You don't know what you're talking about, idiot!" Mr Giuliani shouted at him.
That gives you an insight into his mindset.
During that appearance on Fox, Mr Giuliani claimed he had only spoken to Ukrainian officials about the Bidens at the request of the US State Department.
Rudy Giuliani: "I never talked to a Ukrainian official until the state department called me and asked me to do it" pic.twitter.com/kvPIbPTApQ— Andrew Lawrence (@ndrew_lawrence) September 25, 2019
If the State Department was involved in trying to pressure a foreign power to dig up dirt on Mr Trump's political opponents, that would obviously be a big deal.
Conversely, The Washington Post reports US officials believe the exact opposite - that they were sidelined from diplomacy with Ukraine so Mr Giuliani could step in.
The truth of the matter, and of Mr Giuliani's full role in the saga, should become clearer in the coming days.
If the Democrats do end up pursuing Mr Trump's scalp, Mr Giuliani could lose his first.