For most of Labour's hierarchy - and many ordinary party members - the Scargillite defection is straightforward good news. His opposition to Labour can now be used to emphasise the party's transformation into the natural new party of government. And all without pain, since those who go with him will be few, uninfluential and unmissed. The history of the non-Labour left in Britain is, after all, one of division, defeat and marginalisation.
Such an outcome may be good for Mr Blair and his colleagues, but it is not necessarily great for democracy. Arguably, the creation of a post- Thatcherite neo-consensus, with all main parties committed to low inflation, low taxation, good public provision and pragmatism in Europe, leaves a vast amount of vacated political space on both the left and right.
But the present first-past-the-post voting system makes even the smallest parliamentary representation for such parties practically impossible. Even the millions of votes for the Liberal Democrats at the last election gained them only a score of seats. The Greens in Germany, an important political force in that country for nearly 20 years, would probably never have elected a single MP under Westminster rules.
Little wonder, then, that different tendencies shoehorn themselves into "broad church" parties, competing internally for influence. Mostly these are groups of like-minded people with overlapping views and shifting allegiances. But sometimes their agendas are completely incompatible (as is the case with today's Tory Euro-sceptics and federalists). When this happens, parties can be convulsed by the attempt to resolve issues that, rightly, should be the province of the electorate. In the end, voters do not always get to make the choice over Europe or (to pick an example for the future) over the size of the welfare state, because all parties have made a similar decision about their policies.
Presumably, this is one reason why Mr Scargill has always been a firm supporter of electoral reform, seeing it as a necessary condition for the success of a genuinely socialist party. With a more proportional system, we could well see a centre-left party (Labour and Lib Dem), a centre-right one (Major, Howard, Heseltine and Shephard), one on the left (Livingstone, Abbott, Skinner) and, on the opposite end of the spectrum, the Portillistas. Perhaps some Greens would be in there, too.
But Mr Scargill, appalled by what he sees as the irreversible betrayal of all he holds dear, has not felt able to wait until after the election of a Labour government and the redemption of Mr Blair's promise to hold a referendum on electoral reform. He wants to be in a position to oppose Prime Minister Blair from day one of the new era. If there are stakes around, Mr Scargill will want to do the driving. And this shows impatience, rather than judgement. He is doomed to fail.