We saw it in the virulent rhetoric with which the remnants of the old Progressive Conservatives attacked Reform/Alliance while sparing Jean Chretien's Liberals.
Now we may see the same emnity between the Greens and the NDP:
Green Party Leader Elizabeth May says she's been trying for months to get the NDP to talk about ways the two parties can co-operate on shared priorities, but the party has kept the door firmly closed to her overtures.
She was reacting to NDP criticism over the announcement this week by May and Liberal Leader Stephane Dion that neither leader would run an opponent in the other's riding.
The NDP has called the move undemocratic, and former party leader Ed Broadbent revealed Friday that May had called former Canadian ambassador to the UN Stephen Lewis to try and get him to broker a deal with New Democrat Leader Jack Layton.
She admitted she has been frustrated with Layton's lack of co-operation, and turned to her old friend Lewis to try and open up the lines of communication.
"What the hell is wrong with Jack Layton that he can't answer a phone call?" she said on CTV's Question Period.
"I don't understand this. He talks to Stephen Harper all the time. Surely, our shared values are much closer between the NDP and the Greens."
Leave aside the petulant whining of a teenage wallflower who can't catch the eye of the high school football quarterback.
Jack Layton doesn't return her calls because the Green Party has taken the place that the NDP held for the past little while: occasional lenders of their social conscience, policy platform and stop-the-Tories votes.
Layton knows he'd just be a third wheel in the relationship.
They can't both have the same spot in Dion's affections.