Although not a member - or even a supporter - this is his message.
Be and open. Say "we want independence and we want to see Wales taking her place among the world's nations."Amen to that.
Being honest also means saying: "if Wales was independent right now we would be poorer by far".
Accept the reality that few will be swayed by such a prospect: "We serve the people of Wales and don't want to make you poorer. On the contrary our aim is to stabilise the Welsh economy to the extent that the Welsh people can choose independence without becoming poorer.
"Unlike the other parties, we have no split loyalties and nothing to distract us from our goal.
This may take a decade or two, even three. But Plaid is about more than that:
"Perhaps wealth is enough for some but Plaid has a higher purpose. When we reach our economic goal, we appeal for you to support our goal of independence.
This is the choice facing people: "Even then, independence will be your choice."
That is a radically different framework to the other parties, whose Welsh branches can only beg for more crumbs from london's table. We seek powers to achieve our goals.
Holtham also calls for a leader with the chutzpah and self-confidence of Alex Salmond.
I would take issue with Holtham on two counts. Firstly is that our current relative poverty is somehow natural. We are poorer because we are part of the British state and do not have control over our natural resources and energy sources. Secondly, that it is possible to rectify that economic imbalance and lack of social justice within that state. The current legal set-up under the Government of Wales Act 2006, e.g. regarding control over water resources, explicitly rules out the Government of Wales having any control over our greatest asset.
It follows therefore that political change, i.e. independence, can lead to greater economic wealth and social justice rather than simply the other way around.