He may not be trashing votes for National - yet. But many voters pulled National's way by Key's positive attributes will be having a serious bout of eyebrow-raising.
Key's abrupt ending of his press conferences looked like the pressure is getting to him. It made him look shifty and weak.
The puzzle is why someone who handled the Pike River mine disaster and the Christchurch earthquakes with aplomb is tripping up on something trivial in comparison.
There is clearly little by way of political dynamite in the tape that is not already in the public domain.
But having made the mistake of raising the question of media ethics and going to the police, Key is now hamstrung. He has hoist himself with his own petard and cannot credibly now agree to the tape and transcripts of the meeting being released.
But doing nothing is not an option either, as National's opponents will continue to feast on what has already emerged from the now-infamous cup-of-tea meeting.
Key may be gambling on the affair not having a huge impact on voter behaviour.
He may be right. But it is having a huge impact on National's campaign. Key is the focal point of that campaign. Questions about the meeting will keep coming.
National Party strategists have clearly been relying on the story running out of steam. Instead, it has continued to have a life of its own. What will really worry National is that for the first time in a long time, the party has lost control of events.