But that's what I am now. I paid my three quid and I'm officially a registered supporter of the Labour Party. I had to declare that I agreed with the aims and values of the party, of course, but that wasn't too hard, since the new Clause IV introduced by Blair was deliberately mushy and meaningless. Do I approve of a world 'where we live together, freely, in a spirit of solidarity, tolerance and respect'. Yes, that sounds quite agreeable. Who's going to argue? (Apart from the likes of Nick Griffin, Robert Mugabe and Donald Trump.)
So it turns out that I do have the right to vote. Morally and politically, Labour may have been daft to sell me that right, but I've got it now. And I'm doing my best to use it dutifully, because - as Clause IV says - 'the rights we enjoy reflect the duties we owe'. And I've promised Labour that I'm in agreement with that.
I'm taking this vote seriously. Over the last fortnight I've written around fifteen thousand words as I've worked my way through newspaper archives, trying to get a clearer picture first of each of the candidates for deputy leader, and now those contesting the leadership: Liz Kendall, Yvette Cooper, Andy Burnham and Jeremy Corbyn.
My aim has been to identify the candidates who I think are best for the Labour Party. Not, you'll notice, for the country. And certainly not for me.
Because I'm shallow and easily bored. I like to see Westminster as a soap opera and I like big storylines.
In an ideal world, my preference is for all four of the major national parties to break up and to regroup in a different arrangement. The current set-up isn't working. Better than that, I'd like to see proportional representation so that we could have more parties, For a start, in my new improved system, there'd be four Labour parties, one each for Scotland, Wales, England and London.
But that's not on offer. And anyway I think it would be dishonest and dishonourable of me to abuse my place as a guest of the party by trying to trash the place. So I shall be respectful, and be guided by the consideration of who will stand the best chance of helping Labour rebuild and go on to contest a general election.
Not that I think any of them are in with much of a shout of winning in 2020, so steep are the odds against the party. But denying the Tories a majority is well within Labour's grasp, and even a minority government is a reasonable aspiration.
In that process, I don't believe that policy is particularly important. Broad direction and philosophy count, but detailed policies don't.
And, one final consideration, I know that it's not a very inspiring slate of candidates. As I've said before, it's probably the worst in my lifetime - worse even than in 2007, when there was only one name on the ballot paper and that belonged to Gordon Brown.
But still, despite all the limitations, despite everything, a choice has to be made.
And my decision is that I shall cast my vote for Liz Kendall.
Which has come as a surprise to me. She was probably in third place in my mind when the deadline for nominations arrived. But the more I think about the state of the party, the more I think that she's the only one who might stand a chance of winning the seats that Labour needs to win.
She's ludicrously inexperienced and has yet to display the kind of leadership that she would need, but I think she has the potential to do so. Certainly she seems to be the only one capable of thinking new thoughts and arguing for a new position. Neither Burnham nor Cooper have distinguished themselves in this campaign.
The only other serious candidate is, bizarrely, Jeremy Corbyn. Not for anything he's done, more for the campaign that has grown up around him. There is an argument to be made that he stands far and away the best chance of bringing back some nationalist voters - those who opted for UKIP or the SNP in the general election - and might get a few Greens on board. There might also be a rise in turnout in safe Labour seats. Those new recruits, however, would, I'm convinced, be massively outweighed by a voting collapse in the South and the Midlands, precisely the areas where Kendall would be strong.
I don't believe that the surge in membership is stable or sustainable, and I suspect most of the new recruits will melt away regardless of the outcome of this election. Nor have I seen any evidence that Corbyn's supporters have the ability, or even inclination, to persuade doubters. There is also the impression of disunity that would be given by Corbyn's parliamentary colleagues. This may not be the direct consequence of Corbyn's actions, but it is the political reality. And I cannot see how he could command support in the country if he couldn't get it in the Commons.
And talking of reality: I recognise that Kendall isn't going to win. I understand you can get odds of 100-1 against her doing so, which in a four-horse race isn't too impressive. Which means that, as things currently stand, I think the Tories will win the next general election.