Why won't John McCain say this?

An accurate summary of the US Presidential campaign from Melanie Phillips in the Spectator:

You have to pinch yourself – a Marxisant radical who all his life has been mentored by, sat at the feet of, worshipped with, befriended, endorsed the philosophy of, funded and been in turn funded, politically promoted and supported by a nexus comprising black power anti-white racists, Jew-haters, revolutionary Marxists, unrepentant former terrorists and Chicago mobsters, is on the verge of becoming President of the United States. And apparently it’s considered impolite to say so.