If I'm guessing right, the "no accepting floor-crossers" rule-and as I understand it, it is only a caucus rule, not formal party policy-was instituted in response to former CCF leader Hazen Argue's treacherous act, at a time when the party only had about nine seats, of defecting to the Liberals after the NDP refused to elect Argue as leader, even though what Argue did was to cross the floor away from the party.
(btw if anybody knows of another explanation for this rule, please share it here).
At this stage, what is the point of keeping this particular rule?
It's not as if the rule has done anything to stop sitting NDP MPs from defecting to other parties. It's not something most voters know or care about. If anything, the rule is comparable to the NDP pledge to abolish the Senate or the Australian Labor Party commitment to replace the British monarch as head of state with an elected but powerless president-something that sounds virtuous but is, in practice meaningless-Australians while never ditch the House of Windsor, the Senate will never approve a measure that puts itself out of existence, neither of those changes would make any real difference in the lives of ordinary voters, and it does nothing for the cause of progressive, transformative change to turn away MPs from other parties who have been won over by the NDP's message. It's worse than gesture politics, because the gesture is not only meaningless, but invisible-like giving someone the finger with the lights off.
If the issue is accountability to the voters, why wouldn't it be enough to set up a rule that floor crossers must seek an NDP nomination within six months of crossing, and must stand down at the next election if the fail to gain a nomination?
Also, how is it that, with the supposed floor-crossing ban in place, Robert Toupin, who'd been elected as a PC MP from Quebec, was allowed to sit as an NDP member at one point in the Eighties(granted the guy didn't stay long, but he was technically the first Quebec NDP MP for a year or so)?