It’s the Big One. Super Tuesday. My favourite day in the American political calendar, other than election day itself.
Today is when we learn what sort of mood Americans are in. Are they placid or angry? Do they want evolution or revolution?
Millions of people in 14 US states are voting in the Democratic presidential nomination contests today. Oh, and don’t forget the fine Pacific Islanders of American Samoa - they too are having their say (though sadly I haven’t seen many reporters managing to get assignments there).
Super Tuesday could be the day that decides who faces Donald Trump in the November showdown. Democrats in the mega-states of California and Texas are among those voting today. So it matters.
But that sound you hear? That’s the sound of the Democratic party establishment is panic mode. The moderate, centrist party elite are terrified by the rise of Senator Bernie Sanders, and are doing everything they can to stop him before he can secure an unassailable delegate lead.
Overnight in Texas, three former candidates all endorsed Joe Biden. Beto O’Rourke, Pete Buttigieg, and Amy Klobuchar all shared a stage with the former Vice President and praised his unifying message.
That’s a barely-coded attack on Bernie Sanders’ radical agenda - a socialist wish-list that many in the establishment fear will alienate heartland Americans and cost the Democrats the White House for another four years.
That’s why the fire alarm is going off in the Democratic Party HQ. They need to stop Bernie and fast.
But it may not work. That’s because you can’t contain the enthusiasm and organising power of the Sanders campaign. And this is not an era that the Establishment has been able to shape. So Mission Stop Bernie may fail.
Senator Sanders has turned the assault to his advantage, declaring that his agenda is a threat to the the entrenched interests of the rich and the powerful.
“Look, it is no secret,” he declared overnight, “that there is a massive effort trying to stop Bernie Sanders, The corporate establishment is coming together. The political establishment is coming together and they will do everything. They are really getting nervous that working people are standing up."
By late tonight we may know whether the Democratic Party is in the hands of its progressive, radical wing or under the control of the party machinery.
Super Tuesday should, in theory, be a clarifying event. But there is another scenario: That Biden and Sanders both emerge strengthened. And then this fight for the soul of party will go on for months - all the way to the convention in Milwaukee in July.
If that’s the case, expect not clarity, but confusion; not unity, but recriminations.
Meanwhile, in the UK, Correspondent Rupert Evelyn spoke to Bernie Sander's brother, Larry, as he cast his vote: