Admirers and detractors of Margaret Thatcher can agree that she will be remembered as one of the key political architects of our times. Along with her soulmate, U.S. President Ronald Reagan, she broke decisively with the post-war Keynesian welfare state and ushered in the still-enduring age of neo-liberalism.

Lady Thatcher and her key advisers, such as Keith Joseph, were intellectually grounded in the work of the most prominent foe of John Maynard Keynes, Friedrich Hayek, and his American disciple, Milton Friedman. Her government explicitly set out to reverse the post-war growth in the economic and social role of democratic government, and to thereby restore business profitability and "confidence."

Here's some free advice for a couple of would-be Canadian prime ministers who are both in the news these days, the NDP's Tom Mulcair and the Liberals' Justin Trudeau: Hammer Prime Minister Stephen Harper on the economy.

Both of them were with their party faithful yesterday -- Mulcair at the final day of the NDP's policy convention in Montreal and Trudeau at his coronation as Liberal leader in the evening in Ottawa. Either of them, it is said here, has the potential to form the next government of Canada if the planets line up the right way.

But that means, to succeed, something is going to have to go wrong for Harper -- because, as we pretty well all know, more often than not opposition parties don't win elections so much as governments lose them.