Will Hillary Clinton's pitch unite divided states?
All week she has enjoyed the support of some truly big hitters. The line-up has been impressive: President Obama and Michelle; her own husband, Bill; Joe Biden; Bernie Sanders.
But ultimately Hillary Clinton had to make her own pitch. You don't become President of the United States without being a powerful advocate for yourself.
And that is exactly what Hillary did last night. She promised to bring her party and her country together.
She accepted the nomination of her party and then explained that she wouldn't just be Commander-in-Chief. She would be Uniter-in-Chief, even Compromiser-in-Chief.
It's a message that should in theory resonate in a divided country. But it also raises questions.
Can Mrs Clinton - such a controversial and polarising figure - really expect to be seen as a healing force in American politics? It is not clear that this speech will have won over her critics, who feel that she is dishonest and untrustworthy.
But her attacks on Donald Trump may have been more successful. She accused him of cheating his workers, of defending Vladimir Putin and Saddam Hussein, of being erratic and dangerous.
The two parties' conventions are now over. The Democrats have chosen a figure of the establishment, although they have broken a gender barrier of epic proportions. The Republicans have chosen the greatest maverick, and most unlikely nominee, in the history of American politics.
In other words, quite a contest lies ahead. Both candidates have exceptionally high negative ratings. Both are going to make this a deeply personal race at a time of national anxiety.
Although polls show it is going to be close, it seems likely to me that Hillary will pull ahead and win the White House. She has a disciplined team, a positive message, powerful surrogates, and remarkable resilience.
And yet no one predicted Donald Trump would get this far. So underestimate him at your peril.
There is anger in the country, a frustration - what even Mrs Clinton called a "fury" - that makes this election impossible to project. There could be many more twists.
Hillary Clinton did herself a favour last night. But the contest is not over. For many American voters, tuning in after a year of noise, it is just beginning.