All eyes were supposed to on Capitol Hill yesterday as Donald Trump finally secured support for his "historic" tax reform plan, which he believes will be the biggest achievement of his administration.
Instead, America's attention switched as an unexpected political bombshell exploded less than a mile away at the E.Barrett Prettyman District Courthouse.
There, Michael Flynn, Mr Trump's former national security adviser and close confidante, a man accustomed to chatting one-on-one with the president in the Oval Office, delivered a potentially Brutus-like wound to Mr Trump.
In the previous 24 hours Mr Flynn, always regarded by Mr Trump as a staunch loyalist, had decided to co-operate with Robert Mueller, the special counsel investigating links between the president's campaign and Russia.
Mr Mueller had placed intense pressure on Flynn, threatening to bring legal proceedings against his son, Michael Flynn Jr, unless he agreed to "flip" and tell everything he knew to the investigation.
Flynn, 58, looked grim-faced as he arrived at court. He was required to take off his jacket and waist belt, and to hand over his glasses case, as he went though security. The former Army general sighed as he did so.
Profile | General Michael Flynn
In the cavernous Court Room 14 on the fourth-floor he sat at a wooden table between two sharp-suited lawyers, a pad of paper and a large black coffee pot in front of him.
Judge Rudolph Contreras, a bespectacled and stern figure, asked Flynn to stand. A large US flag was positioned to his left.
Flynn was then required to answer questions every ordinary defendant has to - his age, whether he was addicted to drugs, if he was mentally unstable.
When the judge asked for his plea he stood slightly stooped, appeared to pause for breath, then responded in a quiet, slightly hoarse voice: "Guilty, your honour."
He looked a broken man. One of the two lawyers standing on either side repeatedly put an arm around his back as his head dropped.
Flynn was informed by the judge that his new criminal number was 17-232, that he potentially faced up to five years in jail, a fine of up to $250,000, and possibly having to pay the costs of his own imprisonment.
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The judge then produced a plea agreement, a stack of A4 paper, and handed it to Flynn to confirm his signature was at the bottom. It may contain the names of the "senior officials" in the Trump team Flynn has now agreed to give information to Mr Mueller about.
The judge asked the prosecutor if he wanted to read it aloud, but he declined to do so.
As he left court Flynn scurried into a court elevator, folding his arms tightly and bowing his head.
He ignored shouts from members of the public that included "Did you betray your country?" and "Did Mueller threaten your son?"
It was probably not coincidence that he then went straight to his son's house. Michael Flynn Jr, holding Flynn's grandson, opened the door and Flynn touched the baby on the head.
From Mr Trump at the White House there was no immediate comment. But if he has privately given his former adviser a nickname it is probably "Flipper Flynn".
This was the biggest scalp yet for Mr Mueller. Flynn's co-operation represents a lightning rod that can take him deep into the heart of what went on during last year's election.
Flynn was a leading member of Mr Trump 's campaign and served for 24 days as national security adviser before being fired for lying to Vice President Mike Pence over his contacts with Sergey Kislyak, the Russian ambassador.
Mr Trump had continued to defend him fiercely though, and Flynn's fate was at the heart of the president's decision to fire James Comey as FBI Director on May 9. Mr Comey claimed the president had asked him to back off investigating Flynn.
Flynn, a former director of the Defense Intelligence Agency, was also being investigated over claims he discussed removing a Turkish cleric from America to Turkey for millions of dollars.
The alleged plot would have seen Flynn and his son paid $15 million to move Fethullah Gulen, a Muslim cleric blamed by the Turkish authorities for a recent coup.
That allegation was not contained in the charge of lying to the FBI that he pleaded guilty to, and appeared to have been set aside by Mr Mueller in return for co-operation.
Meanwhile, on Capitol Hill, Republicans said they had the majority they needed in the 100-seat Senate to pass what would be the biggest overhaul of the US tax system since Ronald Reagan was president in the 1980s.
Amid frantic last minute negotiations a small number of recalcitrant Republicans, who had been concerned that tax cuts would raise the federal deficit, eventually concurred.
However, the face of Michael Flynn, rather than news of impending tax cuts, continued to dominate television screens watched by Mr Trump in the White House.
On Twitter the president wrote: "Republican Senators are working hard to pass the biggest Tax Cuts in the history of our Country. This is a once in a generation chance."
Mitch McConnell, the Senate Republican leader, announced: "We have the votes!" But few were listening.