Tommy Sheridan has launched his new political party, Solidarity.
BBC Scotland's Stephen Low looks at the prospects for the new organisation and the Glasgow MSP's former colleagues in the Scottish Socialist Party.
Tommy Sheridan has launched a new political party
I can't be absolutely certain, but I'm fairly sure that it is the only political party ever to be launched with the leader being serenaded with The Impossible Dream, sung by his mother.
Welcome to Solidarity - Scotland's Socialist Movement.
But while the redoubtable Alice Sheridan regaled the crowd with her Matt Monroe impression, her son Tommy was concentrating on the real business of the day - trying to disprove the old left-wing adage "unity is strength".
When the astonishing vitriol of the split in the Scottish Socialist Party is put to one side, the reality of the situation is that where there was one party there are now two.
One is in favour of an independent socialist Scotland. So is the other.
One claims to be the genuine political alternative. So does the other.
Tommy Sheridan claims that this is a good thing.
"Voters now have a choice of two similar political parties," he told listeners to the BBC's Sunday Live a few hours before launching Solidarity.
The message is not new - and if people didn't vote for it last time, what compelling reason will change their minds this time?
He maintains that this will not necessarily split the left vote, arguing, in essence, that there are more than enough votes to go around.
It is not an entirely untenable position.
Turnout at the last Holyrood elections was a mere 49%, so it is possible to argue that the Scottish Socialist Party and Solidarity need not slug it out for each other's votes, but rather encourage half of the adult population who do not vote to exercise their franchise.
But whether Mr Sheridan will be able to do that is a quite different question.
Reluctance to vote is not evenly spread in Scottish society. Generally speaking, the poorer you are and the younger you are, the less likely you are to vote.
As appeals to both are at the heart of Mr Sheridan's political message - after all, he spent the first decade of his political life selling Militant newspaper emblazoned with the slogan "For Marxism and Youth" - he might expect to score quite highly.
But set against that is the fairly obvious point that the message is not new - and if people didn't vote for it last time, what compelling reason will change their minds this time?
And among those who did vote, data extracted from the Scottish Social Attitudes Survey by Professor John Curtice of Strathclyde University appears to show that support for the SSP at the last election was strongest not from those at the margins of society, but those with university degrees.
Likewise, support was higher among employers and professionals than those in jobs classed as routine - and these are all groups who are likely to be voting already.
More relevant, perhaps, than Mr Sheridan's rhetoric of "hundreds of thousands of socialists out there".
Certainly more verifiable are previous election results. These tend not to back up the idea of radical progress being inextricably linked with a multiplicity of left-wing parties.
In 1999 the SSP was not the only lefty kid on the block. The Socialist Labour Party, led by Arthur Scargill, also fielded candidates.
It actually received more votes than the SSP but failed to get elected because its votes were too thinly spread.
Had the votes not been split, then there may have been more than one candidate elected to the left of Labour.
That example is one that everyone directly involved in the SSP split knows well.
The success in getting Tommy Sheridan elected in 1999 hugely increased the visibility of the SSP - and effectively ended any chance of a breakthrough by Scargill's party.
The next Scottish Parliament election takes place next year
The possibility that success for one of the socialist parties at next May's election could mean irrelevance for the other is real.
But does this political storm in a far left teacup really matter?
The answer has to be yes.
Currently the SSP has six seats in the Scottish Parliament. The overall majority held by the current Labour/Liberal Democrat coalition is five.
If the split in the SSP were to cause the loss of most or all of the MSPs the "outside left" currently hold, the effects could be crucial - determining, for example, whether the Scottish National Party is able to take power or whether the Greens are asked to be part of a coalition.
Time to reflect
Of course both sides may succeed in tapping previously unreached areas of support.
They may both establish a parliamentary presence with, say, Tommy Sheridan representing Solidarity in Glasgow and John McAllion representing the SSP in the north east.
Alternatively, they may all have to spend time reflecting on Tony Benn's aphorism that there are too many socialist parties and not enough socialists.
But then again, as Alice Sheridan put it so euphoniously, her son is here "to dream the impossible dream, to fight the unbeatable foe, to bear with unbearable sorrow, to run where the brave dare not go".