Headline news: The conventional wisdom wilts during the course of Britain's snap election cycle

As you can see from the first two articles, April's conventional wisdom -- "prospects look promising", "probably headed to a big win" -- did not hold up during the next 52 days.

Tuesday, April 17.  The New York Times

Certainly, the Conservatives’ election prospects look promising. They are riding high in the opinion polls, with the Labour Party under Jeremy Corbyn in disarray, the centrist Liberal Democrats weak and the fractious far-right U.K. Independence Party, if anything, more a threat to Labour than to the Tories.

Tuesday, April 17.  FiveThirtyEight

But May’s move isn’t risk free. In fact, if the final polls come within a couple of percentage points of the actual vote on June 8, it will be something of an upset. Polls in the U.K. have a history of inaccurate performance, with average errors that more than double the ones in American presidential elections.

Tuesday, May 30.  The Guardian

So much for crushing any meaningful opposition.  Instead the election has been about May’s dissipating authority, her almost obsessive commitment to U-turns, her declining personal ratings, tightening polls and a deeply impressive Labour insurgency. May didn’t appear the “strong” candidate last night. She appeared shaky, on edge, falling back on a strategy of boring Britain to death with waffly, empty answers

Friday, June 9.  NPR

The Conservative Party loses 13 seats -- and their majority; Labor gains 29.  And the other thing, I think, which I think caught us by surprise was the sheer effectiveness of the campaigning by Jeremy Corbyn, the left-wing leader of the Labour Party who fought a very authentic campaign - quite an old fashioned campaign, in some ways - with big open-air rallies where he really energized people. And they also harnessed social media. And at the end of the day, young people who most people assumed wouldn't turn out to vote, as they don't usually in this country, turned out en masse. And there was a big surge of young voters for Jeremy Corbyn, which was quite an invigorating thing to see in this country.

In the end, the polls didn't matter.  What mattered most was the ineffectual canidates who unwisely called the election in the first place.