Viewed in isolation, Maurice Williamson's resignation would be no election-year turning point.
As a Minister outside of Cabinet holding comparatively minor portfolios (Customs, Building and Construction, Statistics, and Land Information), he was not part of the Government's inner sanctum. The 63-year-old's absence from among the coalition Government decision-makers will barely be noticed.
While his profile briefly soared thanks to his "big gay rainbow" speech during the same-sex marriage debate last year, he has also been in trouble more than once for uttering racially-insensitive remarks. From the liberal right of the party, he comes across as an old-school Nat whose star was already on the wane before yesterday's decision to step back.
Any damage to National, then, is not in the loss of Mr Williamson but in the damaging perception that his "significant error of judgment" brings.
The party's opponents have been quick to point to other alleged or proven conflict of interests involving Key government Cabinet ministers.
Nelson MP Nick Smith resigned as a minister two years ago after acknowledging a similar conflict of interest. Corrections Minister Judith Collins has been roundly criticised - including a telling off from Prime Minister John Key - over contact during a visit to China with a company her husband is a director of. Other ministers in hot water in recent years include Pansy Wong, John Banks, Peter Dunne and Richard Worth. For a Government which Key says sets the highest standards, the line-up of transgressions is an embarrassment.
Williamson is by no means the greatest rogue in this gallery. He admitted phoning the police after a wealthy businessman with close ties to him was arrested on domestic violence charges. Transcripts suggest he was at pains to point out he was in no way attempting to interfere with or influence the police process, simply to ask that the file be reviewed. Still, he "crossed a line" and has paid an appropriate price.
Everyone makes errors of judgment. The difference is that Ministers are supposed to be, and know, better. On the face of it, Collins' lapses were, potentially, far greater than Williamson's. Yet he goes and she remains - even if he is currently planning to stay on as an MP and stand in this year's election.
The latest lapse gifts opponents potent election-year ammunition. The true potential for damage, however, would only be realised if the opposition were sufficiently potent and effective enough to fire it.
Labour leader David Cunliffe has failed so far to invigorate his team or show the public he can build a credible alternative government. His own party's latest loss - of one-time high-flier Shane Jones - is probably more damaging to Cunliffe than Williamson's demise will be for Key.
In politics, perception is everything. Williamson's call to police adds weight to the notion, true or not, that Government members are happy to breach accepted standards of conduct to help wealthy mates or donors to the party's coffers. Not a good look in anyone's book.