" It will be argued, with some justification, that it was made up almost entirely of people who voted Remain in the first place, "
The interviewees on the demonstration indicated that this was not the case

The Telegraph show what I mean by how it will be argued. This is the start of an article, the rest is behind a paywall. It is possible that section completely reverses the introductory tone, but I doubt it:

Berets, juvenile posters, and EU-themed wigs: Did the ‘People’s March’ dispel any of its stereotypes?

According to its official line, the so-called "People’s Vote" campaign is neither for nor against Brexit - it merely wants the electorate to “have a say” on the final deal.
But looking among the many thousands of placards, banners, and t-shirt slogans between Park Lane and Parliament Square in London yesterday, it was curiously impossible to spot a single pro-Brexit message.
The slogans ranged from the mainly conventional and often amateurish - “Stay Sane and Remain”, “We are the People Too” - to various, predictable anti-Tory insults. But there were also the odd jarring or downright offensive notes, including one poster joking about the government’s recent appointment of a suicide minister,...