Create the overhang?

Create the Centre right overhang to block the left from Govt.

Current state of play.

Nats 29%
NZ First on 12%
ACT on 8%

On these numbers the left will win govt – and that is even before taking into account any TPM overhang of say 3 seats.

National cannot get past the ceiling which is around 30% party vote. They can however hold onto around 38 electorate seats (these are listed in the next thread). This presents the centre right with an extremely rare opportunity. A large overhang that dwarfs the lefts overhang and guarantee to
block the left out completely.

Through strategic voting, if we take 9% off National’s party vote (which will otherwise be wasted) and redistribute it to their coalition support parties, that would change the calculus big time.

It could look like this:
NZ First on 17%
ACT on 13%

National currently hold 49 seats in Parliament. Under this scenario they would still hold 38 electorate seats the breakdown could be:

• National: 38 seats (- 11 from 2023)
• NZ First: 22 seats (+ 14 from 2023)
• ACT: 16 seats (+ 5 from 2023)

This ensures the extra party votes for National ARE NOT WASTED, and by not voting for the electorate candidate for NZF or Act but for National the electorate votes ARE NOT WASTED , the Nats should hold the seat.

The larger Nationals electorate seat numbers are over their entitlement for list seats the better. Also on recent polling National WILL NOT win list seats anyway

Create the overhang, electorate vote for National , Party vote for either NZ First or Act, keep the left out, and return the coalition with stronger coalition partners.

I asked Grok to expand:

No, this is not correct. The proposed strategy has major flaws in how MMP actually works and in the assumptions about what National can achieve.

Core problems with the plan

1. National cannot realistically hold ~38 electorate seats on a ~20% party vote
This is the biggest error.
In 2023 National won 43 electorates with 38% of the party vote. Electorate results move with the national swing. If National’s party vote drops by 9 points (to around 20%), they would lose a large number of electorates to Labour (and possibly others). Claiming they still hold 38 seats is highly unrealistic. Most projections and historical patterns show National losing seats in line with a big drop in party support.

2. How overhangs actually work
An overhang occurs when a party wins more electorate seats than its party-vote share entitles it to. Parliament expands by those extra seats, and the overhang seats belong to that party.

However:

• The other parties still receive seats in proportion to their share of the party vote (of the effective votes that cleared the threshold).
• Deliberately tanking National’s party vote to create a big overhang only helps the centre-right if National somehow keeps almost all its electorates. That is the part that almost certainly fails.

3. Shifting 9% of the party vote from National to NZ First + ACT
This would increase NZ First and ACT’s list seats. But the loss of those votes from National sharply reduces National’s total entitlement. The net effect on the centre-right bloc is not a guaranteed large gain — and can easily be a net loss once National starts shedding electorates.

4. Practical risks of the strategic-voting advice

• “Electorate vote National, party vote NZ First or ACT” requires very high coordination. Many voters who switch their party vote also change (or spoil) their electorate vote, or stay home.
• It risks National losing marginal electorates they currently hold.
• NZ First and ACT already have their own voter bases; large transfers on this scale are hard to deliver cleanly.
• Te Pāti Māori can still create a left-side overhang if they hold most of the Māori electorates on a low party vote. That expands Parliament in a way that can help the left reach a majority more easily.

Current polling context (mid-2026)

Recent polls have National roughly 29–32%, NZ First 8–12%, ACT 6–9%. The centre-right combined is often competitive or slightly ahead, but some polls show the left bloc (Labour + Greens + TPM) able to reach a majority, especially if TPM holds most Māori seats. It is not a settled “left will win” situation on every poll.

Bottom line

In MMP the party vote is what primarily decides the overall balance of power. Trying to manufacture a large National overhang by deliberately reducing National’s party vote is high-risk and rests on an unrealistic assumption about how many electorates National can hold on a much lower vote share. It is more likely to weaken the centre-right than to “guarantee” blocking the left.

A more straightforward approach is for centre-right voters to party-vote for the party they most prefer within the bloc (or the one closest to the threshold that needs help), while voting for the strongest centre-right candidate in their electorate. Engineering large artificial overhangs via coordinated vote-shifting is fragile and often backfires.

I then asked : You say it often backfires. Why and give examples were it has backfired

Grok replied

Strategic voting aimed at manufacturing a large overhang (or heavily shifting party votes between coalition partners) often backfires for several practical reasons.

Why it tends to go wrong

1. Voters do not coordinate perfectly
   Only a fraction of the targeted voters follow the exact instruction (“party vote X, electorate vote Y”). Others switch both votes, switch only one, stay home, or ignore the call. The actual transfer of votes is usually much smaller and messier than the plan assumes.
2. Electorate results move with the party vote
   A big, deliberate drop in a major party’s party vote almost always costs it electorate seats. You cannot reliably keep 38 electorates while cutting the party vote by 9 points. The two are linked through the national swing and local candidate viability.
3. Misjudging the numbers creates the opposite effect
   If too many voters leave the major party, it can lose more seats than the smaller partners gain. If too few leave, the hoped-for boost to the minor parties fails to materialise and the major party still loses list seats.
4. Threshold and coat-tail risks
   Boosting a smaller partner only works if that partner clears the 5% threshold (or already has an electorate). Misjudging the scale can leave the smaller party short, wasting the transferred votes.
5. Coalition leverage and internal damage
   A major party that deliberately weakens its own party vote often ends up with fewer list MPs (including senior figures) and less bargaining power inside the eventual coalition.
6. Public and media reaction
   Open campaigns to “game” the system can look cynical, demotivate some supporters, and give opponents an easy attack line.

New Zealand examples and patterns

• Epsom-style electorate deals (National voters giving their electorate vote to ACT while keeping the party vote for National) have repeatedly kept ACT in Parliament. However, they often delivered fewer “coat-tail” list MPs than hoped when ACT’s party vote stayed low. The deals worked for survival but under-delivered on the larger seat boost that some advocates expected.
• Historical attempts to prop up small partners (e.g., National signalling support for United Future in Ōhāriu in earlier elections) produced limited lasting benefit. The small party still struggled, and the arrangement sometimes created local resentment or diluted the major party’s own vote.
• Broader strategic splitting has frequently produced incomplete or counterproductive results. When voters are urged to shift large numbers of party votes away from a major party, the actual net transfer is hard to control. Analysts have repeatedly noted that deliberate large-scale attempts to create an artificial overhang by tanking a major party’s party vote while hoping to hold most electorates are high-risk precisely because the electorate seats tend to fall as well.
• In general, New Zealand experience shows that modest, well-understood tactical voting in a single electorate (such as Epsom) is more reliable than ambitious nationwide plans that require tens or hundreds of thousands of voters to move in a precise, coordinated way.

Germany’s experience with overhang seats also illustrated perverse incentives (including situations where extra votes for a party could effectively reduce its overall strength in some scenarios). Those problems were significant enough that Germany later reformed its system.

Bottom line: Small, local tactical votes can work. Large-scale engineered overhang strategies that rely on a major party deliberately surrendering a big slice of its party vote while somehow retaining almost all its electorates have a poor track record because the coordination is imperfect and the electorate seats are not insulated from the party-vote drop. That is why most serious analysts treat them as high-risk rather than a reliable way to “guarantee” a favourable outcome.