Gordon Brown is compared often with previous Labour leaders. Some days he is Jim Callaghan, a Prime Minister doomed never to win a general election. On other occasions, usually when an opinion poll is published, Brown is compared to Michael Foot, leading Labour to previously unimaginable depths of unpopularity. Occasionally comparisons are made to Tony Blair, as some in the Labour party wonder why Brown agitated so long to remove his predecessor only to adopt a similar tactical approach.
Inevitably there are flaws in each of the malevolent, trouble-making comparisons. No two individuals are the same. Circumstances change. Brown is in a different hole to the ones occupied by various predecessors. Still, reading Brown's increasingly convoluted arguments for extending the period suspects can be held without charge, I was reminded of another Labour leader. Brown has become Harold Wilson, a leader who schemed artfully and sometimes desperately in the 1960s and early 1970s in an attempt to keep both sides on board.
In an article for The Times Brown insisted he was responding to the changing demands of national security while at the same time upholding civil liberties. Here was a Wilsonian attempt to square a circle if ever there was one.
The Prime Minister explained that he was going ahead with an extension to 42 days. There would be no going back on this. But the extension would only apply if the police and the Director of Public Prosecutions backed the decision. Then the Home Secretary would have to get parliamentary approval, at which point the judiciary must oversee each individual case. After which there would be independent reporting to parliament and the public in all cases.
If such a sequence is applied, it will take nearly 42 days to get permission to hold suspects for 42 days.
I would not be surprised if Brown announces that as another protection he will allow the public to vote on an extension in the format of Britain's Got Talent, with Ant and Dec putting the question: Who's up for 42 days? The safeguards are accumulating fast.
Probably Wilson would approve of the Brownite efforts to navigate his away through the conflicting sides, although I wonder whether he would have got in such an unnecessary contortion in the first place. A previous great hope of the centre-left, Wilson conjured compromises when none seemed possible, achieving a semblance of unity when none existed.
There were many equivalents to Brownite scheming. Ultimately Wilson gave his support to Britain's membership of the Common Market, but only once the terms had been "renegotiated". He supported some cuts in public spending to the fury of the left, but not to the extent that the centre-right of his party had wanted. The list of compromises is endless.
With the same opaque pragmatism Brown yearns to rebuild the wide, but shallow, new Labour coalition. He is tough on terror but the protector of Britain's historic civil liberties. Currently the British Prime Minister looks so tired, if he smoked a pipe he would even resemble Wilson slightly, a leader that stooped with premature age burdened by the strains of keeping a divided party together. Now it is the new Labour coalition, which extended well beyond the confines of a single party, that Brown seeks to revive.
There is a big difference. Wilson was responding always to unavoidable circumstances. Brown chose to revisit the thorny topic of detaining suspects without charge. Why did he choose to do so? Probably there is more to it than the cliched answer, that the policy allows him to be "tough" on terror compared with the Tories who are "soft".
No doubt it must be genuinely intimidating for a new Prime Minister to contemplate the threat posed by terrorism, the responsibility of acting and the need to be seen to have done all that was possible if another attack occurs. Anyone who has seen the intelligence is daunted by it.
But there are other reasons why Brown uses up much-needed political capital on the liberal side of his dwindling coalition. One of his ministerial allies, who privately despairs of the measure, puts it down to the highly charged build-up before Tony Blair's departure. According to the ally, Brown became fearful that Blair would use his experience of dealing with terrorism as an excuse for staying on in power.
Suddenly Brown gave lots of speeches on terrorism when he was still Chancellor of the Exchequer. He came to regard it as a pivotal test of his suitability for the top job. Brown made the move partly as a way of asserting prime ministerial authority.
From both a practical and political perspective it is proving to be fruitless. Defending the proposals yesterday, the Home Office minister Tony McNulty gave the game away by stressing how rarely the police had made use of the current limit. So why in such circumstances use up much-needed political capital in an attempt to extend the limit to 42 days?
With the number of hurdles growing on a daily basis, the level of scrutiny would be such that the new laws would probably only be used in an emergency. Yet there are laws already in place that would allow an extension beyond 28 days in extreme situations. All the political parties support them. In other words even if Mr Brown gets his way the practical implications will probably be meaningless in spite of all the energy draining build-up to next week's vote.
I suspect Mr Brown will avoid a calamitous defeat, but he should be under no illusion about the degree of wary hostility or disappointed resignation he has provoked on his own side, even if he basks in some rare decent coverage in some of the right-wing newspapers.
Over recent weeks Mr Brown has been subjected to a million words of imprecise and contradictory advice: Be bold! Show vision! Be cautious! Cut taxes! Put up taxes! It is a waste of time. He will not change. He is conditioned to be the Harold Wilson of our times, seeking election-winning coalitions to the left and right of him, hoping to outwit the Tories as he does so, rarely inspiring with his big-tent messages. He will remain deliberately opaque, often frustrating his friends and enemies as Wilson did.
I make three brief observations. When I told a close ally of Brown's that his behaviour reminded me of Wilson's I expected an immediate contradiction. Wilson is not by any means a fashionable figure. Instead he told me as if in confirmation: "Gordon always thought that Wilson was underestimated as a leader."
For nearly a decade Wilson survived plots to remove him from figures bigger than those hovering tentatively around Brown, many of them fuming more openly about the inadequacies of their leader.
As Wilson often noted, he won four elections out of five. Brown would give anything to win one out of one. The increasingly farcical manoeuvrings over 42 days will not help him do so.