Big Tent Donkey Dung
As far as we know, none of the senators have turned around and declared Granholm's statement to be "Canadian," though she was born there and seems to prefer its more socialist system of government to ours.
Sure sounds like Granholm, a Democrat, is questioning the patriotism of her opponents, something other Democrats have claimed is the slimiest sort of politics.
Interestingly, Democrats have claimed their patriotism was being questioned even when it wasn't in order to announce what a disgusting political tactic it is.
Maybe this is what is meant by the Democrats having a big tent. The party accepts politicians who accuse opponents of being unpatriotic and also accepts politicians who declare such accusations reprehensible, even when they are not being made.
That is a big tent. It needs to be, with so much donkey dung being tossed about.