It clearly cannot be contained to the sphere of the personal.
The Dharma opens us up to an ontology of interdependence, which radically undermines the distinctions between the personal and the social.
We don't attain liberation through Dharma practice in groups.
That in itself is highly political, because it denies the kinds of politics predicated on atomistic, autonomous individuals.
I'm really not sure how this could be denied.....
Can you point to some teaching by the Buddha where he rejected autonomous persons conventionally? The same arguments that negate the identity of the person can be used to negate the identity of the polis. Certainly the Buddha's intent was not to replace a sense individual personhood with a sense of collective or dependent personhood. His intent was to expose absence of identity, the lack of recognition of which is the primary cause of suffering.
Your "ontology of interdependence" is something that has been abstracted out of Dharma teachings by intellectuals; but it is not point of Dharma itself. The point of Dharma teachings is to overcome that fact of interdependence. The point of Dharma is the personal reversal of samsaric dependent origination.
Where does the Buddha instruct us to use our Dharma conscience to join the political party of our choice, for example the Green Party, The Tea Party, etc.?
The Buddha does
reject the autonomous
person conventionally. It is not a question of finding a place where he does so explicitly, as it is about realising the disjuncture between the kind of conventional person posited by the Buddha, and the kinds of autonomy westerners tend to mean when they say autonomy. Sure there is still a conventional person of some kind, but the kind of conventional person given (by the Buddha) is - necessarily - a process and relational conventional person. i.e. there is no moral autonomy of the kind favoured by western theologians or philosophers, grounded in a concept of soul or rationality or will or transcendental ego. There is perhaps
something akin to what is favoured by the British empiricists - a dispositional theory of agency where there is some kind of autonomy found in choice making....but this is still a very social conception of agency.
I agree that that the argument which rejects individual autonomy also rejects the identity of the polis. But this does not leave us with nothing. Whatever remains is where the sphere of the political may be found (something of a sāmargrī). And I would argue that it is something of a middle way which overcomes the extremes of reifying either the individual or the collective/community, which are the two poles which contemporary political philosophy tends to gravitate towards.
The question of dependent origination probably lies at the heart of this conversation; this is where the two truths become important. I think that the Dharma leads us into an apprehension of the dependently originated nature of things, not away from dependent origination per se. But I'm fairly sure you think otherwise - and this is probably the reason for our disagreement.
Obviously the Buddha does not instruct us to join a political party
- but it does not follow from that that the Dharma is distinct from politics. For many reasons - namely that politics is not reducible to party politics and that a contemporary Buddhist cannot read the Buddha's advice in the Nikaya's and apply it as if we are still in ancient India (i.e. obviously there was not party politics taking place there).