The surprising emergence of a candidate from the radical left has undoubtedly enlivened what would have otherwise been a torpid leadership debate.
But the prospect of a lurch to the left and Labour banishing itself to a state of long-term opposition is deeply unappealing for those Labourites who still covet power.
A Corbyn victory would extinguish the last vestiges of Blairism, an “ideology” which – whatever one thinks of it – proved successful at capturing the centre ground and winning elections.
Little wonder that some Conservatives have been keen to give the Corbyn bandwagon an extra shove by infiltrating the election process.
With just a couple of days left until the result is announced, it is possible to see just how tricky a Corbyn-led party would be for a host of prominent Labour figures.
Already there are reports that up to eight shadow cabinet members would find it impossible to serve him on the front bench. Corbyn’s vision of an anti-austerity command economy may have re-energised the left, but it is incompatible with those who are anxious to restore Labour’s economic credibility.
Despite all this, in what remains of Scottish Labour circles there is a faint glimmer of hope offered by Corbyn’s rise.
According to those advising Kezia Dugdale, a Corbyn win creates a problem for the SNP.
Having made a huge success of pinching traditional Labour voters by outmanoeuvring it from the left, the SNP would find it tricky to deploy the same arguments if Corbyn becomes leader.
“If Jeremy wins, the SNP would find it very difficult to attack us from the left,” was how one adviser put it yesterday. “For the first time they would have to look at attacking us from the right and that would be very difficult for them.”
But once that straw has been clutched, Dugdale’s advisers have identified another potential downside. The publicity generated by a Corbyn win would make it difficult for Dugdale to move out of his shadow and establish herself as a political leader in her own right.
If Corbyn does triumph on Saturday, his victory will make great newspaper copy and will be a marvellous spectator sport.
But for Labour, it will pose more questions than answers at a time when the party itself is facing an existential crisis.