Leavers are usually very vociferous on social media, I’m sure somecould be persuaded to march - oh, yes, about 200 of them
Seriously…
I’ve already given some of my views on whether it will make much difference. To turn to a couple of additional points that you made - does it demonstrate many “converts”, probably not - in any case we know the opinion polls are still running very close. Does it “say anything new” - no (does it have to?); Does it demonstrate that there is a majority for a further referendum - again, probably not, there were a lot of Revoke posters as well.
But as a demonstration that people are not satisfied with the current handling of Brexit or that serious consideration needs to be given to a softer Brexit, no Brexit or asking the public again I think that it was a pretty convincing one.
The thing about Brexit is that there is no single version which more than a handful will support.
No-one wants no-deal. Even the ERG don’t want no-deal although they probably don’t realise it yet (well, a couple might profit from it but I actually doubt that a majority even of the ERG will do so). You’ll quickly see the “you should have negotiated a better deal” narrative (i.e acceptance that things are shit but denial that it’s their fault) if we leave with no deal.
No-one much wants May’s deal either, especially as it’s not that great a deal.
After that, what? Labour haven’t got as far as a concrete proposal - well, there’s “Common Market 2.0” but I don’t think that is beyond the “just an idea” stage, it’s certainly not policy. It also has the marked difficulty that it involves being in EFTA and the EFTA Nations have politely but fairly firmly said they don’t want us - had the groundwork been started two and a half years ago maybe we’d have swung it, but we have blotted our copy-book too often for it to be feasible now.
Don’t forget that for everyone who marched there will be half a dozen who wanted to but could not. Don’t forget that the People’s Vote campaign has had a million or nearly a million out on the streets not once but twice.
Given that 85% think Brexit is being mishandled, no-one can agree on any actual Brexit plan, nearly 5 million people have signed a petition asking to stop Brexit and a million people have taken to the streets you would expect the government to sit up and take a bit of notice.
Except that the government is presided over by a psychotic, sleep deprived, megalomaniac with tin-pot dictator aspirations who has cloth ears.