Was Jo Swinson’s decision to give Boris Johnson the election he wanted rational after all?

The definitive book on the 2019 election is published today, shedding new light on the puzzle of how it happened in the first place, writes John Rentoul

Jo Swinson, the former leader of the Liberal Democrats (Getty)

Outcome bias is hard to guard against. Because the Liberal Democrats lost seats in the 2019 election, including the leader’s own, it seems obvious that Jo Swinson’s decision to give Boris Johnson the election he wanted was a terrible one. And it may indeed have been a bad decision, but it may not have been as foolish as it looked afterwards.

The authoritative book of the election is published today. The British General Election of 2019, by Robert Ford, Tim Bale, Will Jennings and Paula Surridge, is the latest in the series of academic studies going back to 1945.

It includes a riveting chapter by Professor Philip Cowley on the shenanigans that led to the passage of the Early Parliamentary General Election Act, two years ago last week. He concludes: “Political decisions are often gambles, and just because a gamble doesn’t pay off doesn’t mean it was wrong to roll the dice.”