I find it hard to believe that the conservatives in the Coalition who are apparently chattering about a challenge to Turnbull's leadership if he allows a conscience vote on same sex marriage think they are on a winner here.
I've said before, I think a plebiscite is a good way to resolve a matter of unusual social and cultural consequence - yet I don't doubt that it will go in favour of gay marriage. But having achieved it that way does give a clear societal endorsement to the change - and conservatives won't be able to claim it is just a result of elitist, out of touch, politicians (or judges) knowing what's right for society. From that point of view, I think SSM activists should endorse the policy too. And I think my view on this is reflected in public support for a plebiscite.
Having said that, all sensible people can see how it is going to pan out if a plebiscite is run at the next election, and as such, why should sensible people lose sleep if a government changes tactic and just says "lets vote on it now - the polling is clear on how a plebiscite will go, and has been for years - it can be a conscience vote, and we can stop talking about it and think about other issues."
Those who think it deserves to be an issue to bring down Turnbull just aren't sensible. But they are likely to be completely unable to read the evidence on climate change, too, and make sensible responses to that as well. They just love pushing hopeless causes against the evidence, for culture war reasons.
I think a conservative push to oust Turnbull on this issue would just backfire on them in a spectacular way - confirming in the public's mind that the Liberals are a party at internal war with itself, just as the Rudd/Gillard wars harmed Labor.