[a-priori]

We elect politicians whose full-time jobs it is to understand big and complicated issues, and to decide on our behalf how to deal with them. That includes the right to make and break treaties with other world powers.

Why should something like this be any different?

[dragonwriter]

> We elect politicians whose full-time jobs it is to understand big and complicated issues, and to decide on our behalf how to deal with them.

But, on Brexit specifically, the British people elected a government that made a campaign promise to hold exactly such a referendum, and to abide by its results.

[makomk]

One very plausible theory I've seen doing the rounds is that the government never actually expected to have to follow through on that campaign promise. Strategically speaking it was a terrible idea and Cameron was always pretty pro-EU, but he needed the support of the anti-EU faction of his party, so he promised the vote as a sop to them. The theory goes that he didn't expect to get an absolute majority in Parliament and hoped the other parties would "force" him to to not follow through.