The pall that hung over Parliament this afternoon was heavier than usual for a ministerial resignation.
OPINION: Dr Smith is one of Parliament's longer serving MPs and one of John Key's more capable ministers - despite an occasionally turbulent career.
His fall from grace is as spectacular as it is sudden. But the emergence of a second document raising further questions over his support for ACC claimant and close friend Bronwyn Pullar gave him no choice but to fall on his sword. It was either go or be sacked.
Key was clearly of the view yesterday that while the affair was messy, it would soon blow over. He accepted Smith's contrition and acknowledgement that he erred. But in the cold light of day it would have become increasingly clear that the story was not going to go away. The questions raised by a senior minister using his position to advantage a friend were too serious to ignore. The fact that she was also a National Party activist, and that she had been treated to meetings with senior ACC management with support person, former National
Party president Michaelle Boag, in tow, only fuelled the perception of special treatment. The calls for an inquiry were only going to grow louder.
It is a safe assumption that ACC and the minister's office spent yesterday trawling through the files on instruction from the prime minister's office for evidence of any further interference by the minister.
In the end what they found was a second document that was nowhere near as damning as the one that emerged yesterday. But it was certainly a useful development on which to hang a ministerial resignation.