Take the last election, when the manifesto promised a grammar school in every (major) town (where parents wanted it).
Vigorously espoused by the leadership and the party's high command, Conservatives further down the food chain - such as the then education secretary Gillian Shephard - were considerably less enthusiastic, opining that public memories of the downside of the 11-plus meant there were no votes in it.
Midway through the campaign, a battle meeting was called at Number 10 to thrash out details of a massive press push on grammar schools the following day. The assembled grandees, ministers and aides, complete with draft speech and press release, gathered in the Cabinet room waiting for Mr Major, who had spent the day on the stump.
When Mr M turned up, his mood might politely be described as tetchy. Storm clouds gathering over his head, he read the proffered bits of paper in grim silence before exploding: "Who wrote this rubbish?" Puce with fury, he continued: "I don't know why we're pursuing this grammar-school policy. I've been knocking on doors all day, and there are NO votes in it."
In best Yes Prime Minister style, those present refrained from retorting that the policy's main mover and most enthusiastic advocate was... John Major.