Every Tory leader since WWII has increased the Tory share of the vote in their constituency in their first general election as leader except Mrs May
It appears Amber Rudd’s majority of 346 in Hastings & Rye is seen as a bar on her being Theresa May’s successor as some Tories don’t want the symbolic moment of the next general election to be the Tory PM losing their seat. Nor do they want their leader spending most of the campaign in their constituency trying to hang on when they could be more effective across the country.
But if we look at the charts above, we can see every Tory leader since World War Two, except Mrs May, has seen an increase in their share of the vote in their constituency their first general election as leader. It appears being party leader meets with the approval of your local electorate.
On swings to the Tories, every Tory leader has seen a swing to them except Theresa May, John Major, and Edward Heath, the swing against Heath can be attributed to the snap election called by Harold Wilson which say Labour increase their majority.
In 1992 John Major saw his majority increase from an impressive 27,044 to an eye watering majority of 36,230. By contrast in June Mrs May saw her majority fall from 29,059 to 26,459. The notional swing against Major was from the fact that the previous general election the party in second place was the SDP who by 1992 were defunct, and in Huntingdon both the Liberal Democrats and Liberals stood splitting the vote and allowing Labour to come through the middle to take second place, a situation that seems unlikely to happen in Hastings & Rye.
So long as Mrs Rudd doesn’t run a general election campaign as bad as Theresa May’s 2017 campaign, history suggests Amber Rudd will hold her seat if she’s the incumbent Prime Minister and Tory leader, having such a small majority shouldn’t be a bar on her becoming Prime Minister.
N.B. For Alec Douglas-Home I have calculated the increase/swing as the change from the 1963 by election, as he wasn’t the incumbent at the previous general election. I nearly excluded him from the list given the unique circumstances of his ascension to the Premiership