Bernie Sanders will never be president of the United States of America. His eight-year insurgency is now all over, bar the shouting.
Joe Biden's victory in the Michigan primary last Tuesday saw the last hopes of the 'Bernie Bros' evaporate. The former vice president under Obama is most likely going to be the Democratic nominee to take on Trump later this year. His lead is now almost unassailable, and the coalition of voters he has assembled is broad and committed.
Bar calamity, Biden, on the third time of asking, will win the opportunity to run for US president. Oddly, Biden Vs Trump starts today at 8pm eastern time in Washington, DC with the first head-to-head debate between the Democratic frontrunners. And Sanders could be Trump's greatest weapon. This is Sanders' final campaign, the last stand of his progressive movement. He has little to lose. A dangerous opponent. Debates rarely matter, until they do. A cutting, well-targeted takedown live on national television can have an impact on a campaign - particularly when a candidate is forced into a mistake that confirms a preconception voters had about their candidacy or undermines a foundational strength.
Elizabeth Warren skilfully destroyed the argument that Michael Bloomberg would be an electable candidate by exposing his derogatory comments towards women and the perceived racism of his stop-and-frisk policing programme in New York.
Similarly, in the last election cycle, Chris Christie effectively ended Marco Rubio's campaign for the Republican nomination by forcing him into a repetitious cycle of inane talking points - thus confirming a worry that Rubio was charismatic but insubstantial.
It's possible Sanders will take a conciliatory approach to the debate. Use the moment to push Biden to the left on his issues and take the opportunity to bring the Democratic Party together. By calmly questioning Biden on his policies, he could give his opponent the chance to show the essential Sanders' coalition that he is open to representing their interests.
But Sanders' comments last week should make the Biden camp wary and ready for aggression. Just a few days ago, he said: "On Sunday night, the American people will have the opportunity to see which candidate is best positioned to defeat President Trump". Meanwhile his aides have told The New York Times - off the record - that their candidate sees this as the last chance to challenge Biden on his record.
If Sanders goes for that aggressive approach he may seek to expose Biden's supposed weaknesses around his mental agility, his progressive credentials or his support for agreements like Nafta that are unpopular with the white, working-class voters he requires.
Biden not only requires a win in this debate, he has to come out unscathed. That's not an easy task. He must guard against Sanders' attacks and reach out to the entire Democratic base. But he must also take the opportunity to start honing his attack lines on Trump. The wider public have started paying attention - he can't squander the moment.
These attacks have been designed to dampen down Republican turnout in key demographics - working-class men and white women across swing states such as Pennsylvania.
Trump has a clear plan to fill converted but unmotivated Biden voters with despondency and inactivity. Biden has to do the same to Trump. Throughout much of his presidency, Democrats have attacked Trump on his morality and motives. This won't work. Trump has historically stable approval ratings. His base hasn't been dented. They know he's not moral, they know his motives aren't always virtuous. They knew that in 2016 so they don't judge him by that criteria.
His next campaign demands a new tactic - look at his competence and his delivery, not his comments or morality.
Biden wants to focus the discussion around this election on 'a battle for the soul of America'. This is just fine as a motivating message for his own base - but it does nothing to detract from Trump's support levels.
One of the most effective attacks on Trump so far has come from a previous supporter. Ann Coulter, a controversial right-wing pundit and anti-immigration campaigner, was an early high-profile Trump surrogate. She's turned on him since because of his inability to construct a significant wall on the border.
Trump ran his campaign on the visual slogan of 'Build the Wall'. Its absence is a glaring symbol of his inability to deliver. Democrats don't want the wall, but they could use it as a missing monument to Trump's betrayal of his base.
None of this is to suggest that Trump hasn't been effective. He has. To many of his supporters he's delivered on his promises on trade and on judicial appointments.
But the Democratic campaign has to highlight the weaknesses. And not the weaknesses from the perspective of their voters - they need to undercut his message with Trump sympathisers. Dampen down their enthusiasm and give those wavering, an excuse to justify staying at home on election day.
Trump's ability - or inability - to get things done will be put into starker focus as the US fights Covid-19. Biden's response to Trump's handling of Covid-19 has been more direct - calling out his "adversarial relationship with the truth" but it's now time to go further and wider than the pandemic.
What impact the virus will have on the world, never mind a November election, is the great unknown right now.
Initial polling shows that reaction is dividing down party lines. Last week, 61pc of Republican voters weren't worried about catching the disease, while more than two thirds of Democrats were. Everything - even an undiscerning virus - is partisan in American politics now.
It remains to be seen if this will last.
Will Trump's smokescreen of international travel bans give his voters an excuse to continue their support or will the fallout undermine their trust in his competence and the Trump economy? Biden must do everything in his power to make sure it's the latter.
So tonight, the aim isn't just surviving the dying sting of a vanquished socialist, it's landing the first successful blow on the incumbent interloper.
Lorcan Nyhan is head of careers with The Communications Clinic