Despite the sometimes trenchant public debate on electoral and coalition strategy, the expectation is that the leadership motion at the Labour Party conference in Tralee will be carried.
This not only relates to the merits of the argument, about which reservations remain. It is a confidence issue for the leadership.
Political parties know that it is suicidal continually to challenge their leader. An extreme example is the Ulster Unionist Party, decimated in the Westminster election. Oskar Lafontaine has done the German SPD few favours since he spectacularly resigned in 1999, abandoning them as they face into a general election they have little chance of winning.
Pat Rabbitte is proposing nothing that departs from Labour's traditional practice of forming an alliance with Fine Gael, before or after an election.
What complicates the argument is Labour's short-lived experience of coalition with Fianna Fáil in 1993-94. Talk of forcing "the two conservative parties" together and creating a "normal" left-right divide has evaporated.
The long wait involved in that strategy and its implied preference for "principled" opposition has few attractions.
A Fine Gael-Labour pact by itself is unlikely to produce the numbers to sustain a government. A majority would require a net gain between them of some 30 seats. As the rainbow metaphor acknowledges, other parties or groups are required. Who might they be?
Fine Gael, naturally, has mooted the PDs. Ignoring the exaggerated ideological confrontation between the PDs and Labour, the problem is that two tails could not be wagging the Fine Gael dog at the same time.
The Greens, preferred by Labour, are not anxious at this point to tie themselves down, or to indicate in advance to their supporters the extent of the compromises they have to make to be in government. The least divisive aspect of their programme, the emphasis on public transport, is common to all parties. Otherwise, their input would hardly go beyond policy inflections, or "tweaks", to use Eamonn Ryan's phrase.
A third possibility is seeking support from an organised alliance of socialist Independents, as proposed by Seamus Healy, which could be decidedly awkward to manage.
Without greater clarity, the desire for a complete change of government will have to be pretty strong, if the electorate is to be persuaded to take the risk.
Pat Rabbitte, like Dick Spring in early 1997, excludes Fianna Fáil, not necessarily to that party's detriment. He simply defines his main battlefront. The justifications are interesting.
While it is tempting to present it as a principled stand against the moral and political delinquency habitually attributed by its critics to Fianna Fáil, it is difficult to anathematise convincingly Bertie Ahern and his colleagues over the past eight years.
The greater policy compatibility and the continuing attractiveness of a Fianna Fáil-Labour government to many in the trade union movement is never adverted to, as it might embarrass.
There is validity for all parties in the numbers argument. Subject to making up a secure Dáil position, the smaller or the fewer the coalition partners the more the influence and positions attainable for one's own party.
Hence, other things being equal, Fianna Fáil and the PDs prefer to team up, while Labour's preferred senior partner is the smaller of the larger parties, Fine Gael. This enabled Labour in the last rainbow coalition to occupy the ministries both of Finance and Foreign Affairs.
Alternative policy choices have yet to be spelt out. Talk of a pre-election accord on principles suggests that a joint platform may be quite vague, come election time. It may be that the emphasis will be placed on a change of personnel.
There is a suggestion, even taken up editorially in this paper, that there would be something unhealthy about the public re-electing a government for the third time, even though nothing is more normal in Western democracies, not just in Britain, but in many European countries and Canada and Australia.
While Ireland, like Canada, Sweden and Japan, has a dominant party, the Irish Labour Party between 1973 and 1997 was actually in government more years than Fianna Fáil. They had three full terms, albeit not successive. Labour's best chance of consecutive government terms was thrown away when they broke prematurely, first with Albert Reynolds, then with Fianna Fáil in late 1994.
The last 20 years have been easily the most successful in our history, with many contributing factors that involve a variety of political credits. At the same time, the central role of Fianna Fáil in redressing the economy, creating social partnership and bringing about peace in Northern Ireland, cannot easily be erased from the public mind.
Questions likely to be asked include whether the Labour Party is now essentially a Blair- or Brown-type "new" Labour. Its departing chef de cabinet Fergus Finlay was right in saying in his April Magill interview: "We don't represent working-class Ireland, because it's not what it was 20 years ago. That's why one looks at brands. Our base needs to be built in the middle class, and people who aspire to be middle-class. Some of the old party associations - trade unions etc are no longer relevant." Though never occupying more than a part of that space, vacating it exposes Labour's flanks.
Can one assume that, like "new" Labour in Britain, no frontal attempt would be made to raise income, capital or corporation tax rates, and that indirect taxes, incomplete indexation and increased charges (alias stealth taxes) would carry the burden of additional revenue needed? Going by past form, there might be some shift from infrastructural spending to social services.
Looking at continental Europe today, it is clear the comprehensive social model is in considerable difficulties. The electorate here wants urgent improvements in our current model. Very few want a total change or a collapse of confidence. Reassurance, not just promises, will be needed from advocates of a change of government.