John Key is probably right that more people care about limits on how many snapper they can catch than about the real Fish in the Room, the changes to the Government Communications Security Bureau law. Catch limits are easy to visualise: nine fish today, down to three tomorrow.
Expanding the potential for electronic spying is not only invisible, those awkward initials GCSB hardly roll off the snapper-hungry tongue.
The Prime Minister would be wise, though, not to become too fixated on rolling opinion polls of what people say they find important. If more people tick snapper than spying as a concern, it does not mean spying on their emails is unimportant.
Mr Key would be the first to say the Trans Pacific Partnership Agreement forming a free-trade zone around much of the ocean is vital to New Zealanders' futures. But ask the public in an opinion poll if it resonates, and it would be in the margin of error.
When the Labour-led Government in 2007 forced through the deeply undemocratic Electoral Finance Bill, to widespread criticism including from Mr Key, the issue never rated a blip in polls.
Given a choice between the state of the economy, health, education or immigration, highlighting a concern with how elections could be funded proved all too abstract. Yet it was important and its controversy undoubtedly fed a general public malaise with a high-handed Government.
Undercurrents, not just the white tops, can make a difference to anyone fishing for votes.