He could have made a very interesting argument about the relevance of Christian ethics or something, but instead, he goes rambling off about how we would have to demolish this building and that in order to erase all traces of it:
Moving to Ottawa, the first target for the wrecking ball would obviously be the Peace Tower, the most prominent feature of our Parliament buildings. If displaying religious material on public property at the centre of the universe is “inappropriate” because it goes against Toronto's “general policy of inclusiveness,” surely it would be utterly intolerable to allow the Peace Tower with its prominent scriptural inscriptions to remain standing.
It's really quite a ridiculous argument that he is making, and it is one that skirts around the real issues. Mr. Manning is quietly ignoring the way that religion is often used in the public square to justify marginalizing those who do not subscribe to the same moral or ethical credo.
Consider some of the screeching from the likes of Stephen Boissoin and his friends over at No Apologies over the Buterman case for a moment. (Or Boissoin's 2002 letter for that matter) Here are cases where someone is using religion "in the public square" as a means to justify limiting the rights of others, or to justify blatant discrimination against someone they find "morally repugnant" - on largely religious grounds.
In answer to this, Manning points out that the Charter acknowledges the supremacy of God:
And the Charter could not escape unscathed since its preamble acknowledges the supremacy of God, while its opening clauses seek to guarantee the freedoms of religion and expression, which the wielders of the wrecking ball seek to restrict.
What he blithely ignores is that while the charter does make such an acknowledgement, it never sets out what specific notion of God it refers to. In fact, the very existence of explicit freedom of religion clauses makes it quite clear that no particular god - and therefore, no particular religion - is recognized. It could be the Baptist notion of God, or the Hindu concept of Shiva ... or nothing at all if you are an atheist.
In short, the Canadian Constitution is deliberately vague in this area for good reason.
Contrary to Manning's wild imaginings, there isn't a coherent campaign to erase all traces of religion from the public square. What is really happening is that the assumptions of Christianity are being questioned and challenged publicly - ironically using precisely the same Charter that guarantees freedom of religion.
The really sad part is that for the most part, religions can be a source of enormous social good, and it is only a small, exceedingly vocal, handful who use their religion as an excuse to marginalize others and justify acts of discrimination.