Taking on a job which could politely be described as a hiding to nothing in November 2011, she has transformed the fortunes of the Tories north of the Border.
For a Conservative to be considered as a potential “next First Minister” would have been inconceivable pre-Davidson. When Jackson Carlaw applied that description to his boss earlier this year, it may have sounded optimistic but certainly not impossible.
And it is not just in Scotland that her talent has been recognised, with a switch to Westminster and possible elevation to the highest office all being suggested with varying degrees of seriousness in the past.
Today, as she stands down as leader of the party she says it has been a “privilege” to head, many Scottish Conservatives will no doubt be left wondering what if?
They face the challenge of finding a leader who can relate to the Scottish public in the way that Davidson did, appealing to the core membership while offering a real and believable alternative to floating voters.
Davidson has the magic X-factor – bags of personality to match her political nous, as at ease on the streets talking to OAPs as she is in front of the cameras.
The very qualities also possessed by the First Minister whose warm words on Davidson’s departure likely hide her delight that her most credible challenger has been removed from the game.
“We never had a succession plan,” one party source was quoted as saying after Davidson’s decision to quit was revealed, and that is a massive headache for the party as it looks towards the Scottish Parliament elections in 2021, a General Election perhaps any week now, and very possibly a referendum.
That though is not Ruth Davidson’s problem.
Her stated reasons for standing down are completely understandable, and while the very obvious divisions with London will continue to be the cause for speculation at least for the timing of the announcement, her intention to spend more time with her family and baby son cannot be questioned.
We wish her the best of luck for whatever the future holds.
The Scottish Tory Party, however, will need a great deal more than luck as it plots a post-Ruth future.