(CNN) It could be one of those Washington days that define a political era.

When Supreme Court pick Brett Kavanaugh and his original accuser Christine Blasey Ford deliver dueling testimony on Thursday, they will conjure drama of an intensity unusual even in the Trump administration.

Take it from the commander in chief himself, who said of a day steeped in political, legal and judicial consequences: "I think it's going to be a very, very, important day in the history of our country," President Donald Trump said in New York on Wednesday evening.

In Room 226 in the Dirksen Senate Office building, Kavanaugh will effectively stand trial after three women came forward with accusations about his conduct as a teenager i n the alcohol-fueled youth party culture of the early 1980s.

"I will not be intimidated into withdrawing from this process. This effort to destroy my good name will not drive me out," Kavanaugh will tell senators, while denying all the accusations against him, according to an advance excerpt of his remarks. Kavanaugh also denied new accusations released in Senate Judiciary Committee transcripts Wednesday night.

But first, Ford will step forward to tell her story -- exposing herself to the world, instantly becoming an icon of the social revolution unleashed by the #MeToo moment and putting her own reputation and her family's safety at risk.

"I am here today not because I want to be. I am terrified," Ford will tell the committee, according to an early copy of her testimony.

"It is not my responsibility to determine whether Mr. Kavanaugh deserves to sit on the Supreme Court. My responsibility is to tell the truth."

A person involved in Kavanaugh's preparation for the hearing with senior White House officials said the judge was deeply angry and could show more emotion at the hearing than in his rather stilted interview on Fox News this week. The source added that for the judge it was now as much about clearing his name as a spot on the court.

Samantha Guerry, a friend of Ford, meanwhile told NBC's "Today" show that although Ford was terrified, she was ready for the hearing.

"She's spent quite a bit of time centering herself, and she is fierce and determined and undaunted, so we shouldn't underestimate her. When she shows up this morning, she'll be ready," Guerry said.

Thursday is about far more than a painful and compelling human drama that will be decided not by a jury, but the votes of 100 senators. It is the culmination of decades of political and societal forces that have led up to a political pivot point.

Lives will be affected for decades

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The Judiciary Committee hearing will not only seal or doom Kavanaugh's hopes of reaching the Supreme Court: It will decide whether he becomes the vote that could shape how the nation lives for a generation by enshrining a conservative Supreme Court majority.

If his nomination fails, the partisan bitterness that has festered over the last few weeks will likely be a preview of an even more damaging political breakdown during the search for a new nominee to fill the crucial swing seat on the court.

That fight would weigh heavily on the last weeks of the midterm election campaign, in which Democrats are aiming to at least take back the House -- a scenario that could impose a vise on Trump's presidency, and even lead to impeachment proceedings.

Another leading character in Trump's churning political melodrama, Deputy Attorney General Rod Rosenstein is waiting for his fate to be decided.

Speculation has been rife all week that he will be fired or resign in a meeting with the President on Thursday -- but Trump said at his news conference he was thinking of postponing their chat so he could concentrate on the Kavanaugh hearing.

It's not surprising since Trump often acts as the executive producer of his own presidency, so why would he not wait for a quiet moment to spin out another drama that will transfix Washington?

As with Kavanaugh, the uncertainty around Rosenstein is not just about the threat of one man's meticulously built Washington career being destroyed in a matter of moments.

If he is removed by Trump, in what some critics have branded a "slow motion Saturday Night massacre," a Watergate-era purge at the Justice Department, special counsel Robert Mueller's job could also be at risk since Rosenstein also oversees the Russia investigation.

And yet as the President has presided over the uproar raging around both men, he set off new uncertainty about Kavanaugh's fate Wednesday, despite calling the allegations a "big, fat con job" and strongly siding with his nominee.

As Senate Republicans are pushing for votes on the nomination starting Friday, the President confused the message by saying he could change his mind after the hearing.

"They're giving the women a major chance to speak. Now it's possible I'll hear that and say, 'Hey I'm changing my mind. Hey, that's possible,' " Trump said.

The President might not have been serious, since he also lashed out against women who have made accusations of sexual assault against him personally. But he can hardly have pleased Republican senators with his intervention.

A generational moment

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The reason why Republicans are so determined to place Kavanaugh on the Supreme Court -- come what may -- is that the goal of a conservative majority has become the existential purpose of the Republican Party itself and is one of its few unifying causes.

Indeed, Kavanaugh's elevation as the crucial vote would be the culmination of the rebirth of movement conservatism itself in the 1960s and the path trod by Ronald Reagan, Newt Gingrich and the Tea Party movement of the past decade.

But the treacherous politics thrown up by the Kavanaugh controversy also imperil a Republican Party already in a deep hole with women voters in the midterms.

That's one reason the majority on the Judiciary Committee hired sex crimes prosecutor Rachel Mitchell to question Ford, in place of the 11 middle-aged or elderly GOP men on the committee, some of whom seem temperamentally more at home in the last century.

The furor over the nomination has been exacerbated by the fury of Democrats who saw President Barack Obama's nominee Merrick Garland deprived even of a hearing by Senate Majority Leader Mitch McConnell whose legacy is pinned on the transformation of the court.

It was in that toxic atmosphere that allegations by Ford, another woman Deborah Ramirez and then fresh explosive claims Wednesday by another friend, Julie Swetnick, detonated.

Republicans have accused Democrats or presiding over a last-minute "smear" campaign and character assassination against Kavanaugh.

Democrats charge GOP colleagues of deliberately thwarting the search for truth, by refusing calls for FBI investigations and declining to allow Ford's legal team to call witnesses at Thursday's hearing.

Adding to the frenzy in the leadup to the hearing, Judiciary Committee Chairman Chuck Grassley said Wednesday night the committee has talked to two men who each claim they were the ones who had the encounter with Ford, not Kavanaugh. Democrats were furious at the last-minute surprise, CNN's Manu Raju reports, and Ford's legal team claimed the committee failed "to point out that they found this to be not credible."

"This last-minute attempt that seeks to undermine Dr. Ford won't work," Ford's legal team said in a statement.

At times this week, it has felt like Capitol Hill has been swept by a kind of madness, with new accusations breaking, speculation about Rosenstein and lawmakers snapping at pursuing packs of reporters.

"We sometimes seem intent on stripping people of their humanity so that we might more easily denigrate or defame them and put them through the grinder that our politics requires," Republican Sen. Jeff Flake said Wednesday.

Flake refused to say how he will vote on Kavanaugh. But he will face that choice within hours, since Grassley has scheduled a vote in the panel on Friday in the hope that the machinery of the Senate can grind towards a final vote early next week.

Two other Republican senators, Susan Collins of Maine and Alaska's Lisa Murkowski, have also at times expressed concern at the confirmation process and are potential GOP defectors.

If two Republican senators break ranks and all the Democrats oppose Kavanaugh, his nomination will fall. But several Democrats facing tough re-election fights in states where Trump won big have their own tough choice to make.

Will it be fair?

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Thursday's hearing will also raise fundamental questions of fairness. And perhaps the biggest risk is that despite its deeply divisive impact, it solves nothing.

It's possible that Kavanaugh wilts under the questioning of several experienced prosecutors on the Democratic bench. Or that Ford is undone by inconsistencies in her story.

But given accounts of her character by friends who have appeared on television, it's just as likely that Ford emerges as poised and courageous. Kavanaugh, who has been practicing for his testimony for days with White House lawyers, could also be firm under fire.

What then?

It's conceivable that at the end of the day, Republicans see one truth and Democrats another. If the GOP goes ahead under those circumstances the nomination could enflame the nation's blazing political culture even more.

The hearing also raises some of the most difficult questions involving the handling of allegations of historic sexual assault, that have been sharpened after the #MeToo movement have made women more comfortable coming forward with allegations of alleged misconduct by powerful men.

For instance, who bears the burden of truth -- the accuser or the accused?

And if Kavanaugh cannot prove unequivocally that he is innocent, then should he be prevented from taking up a position on the court? If so, it could be argued that the basic standard of justice -- that someone is innocent until proven guilty -- has been reversed.

Or is a spot on the Supreme Court so instrumental to some of the most sensitive issues in American life that anyone who holds it must possess a character unimpeached by accusations and above all suspicion?