As is typical, the original recipe in McElhone calls for Rye, not Canadian Whisky. It was only the editors (or bartenders) of the Savoy who swapped in "Canadian Club".
Canadian Club is not nearly as assertive as Sazerac Rye.
I'd hazard that the canadian whisky and the vermouth work in concert to dampen the Campari's excesses in the original, rather than compete with it.
Whether they made that swap because American Rye Whiskey was unavailable during prohibition, because Canadian Whisky was preferred behind the bar at the Savoy for some reason, or because smoother blended whiskeys were becoming more fashionable at the time, I cannot say.
Folks who have tried vintage samples of Canadian Whisky tell me that the much of the modern stuff is much smoother.
Modern Canadian brands they suggest for "accurate" substitution include the Canadian Club 12 year and Wiser's 18 Year. Unfortunately, neither of these is easily available to me.
Edited by eje, 19 May 2009 - 09:09 AM.