Could you explain that? I can't think of a situation where putting the candidate I want to win as #1 would cause them to lose. Ranking other close candidates as #2/#3 could cause my #1 to lose, but I don't think voting for someone as #1 alone would possibly harm them.
A is left, B is center, C is right leaning.
Polling shows that voters are leaning:
- 15% BAC
- 15% BCA
- 25% ABC
- 45% CBA
If everyone voted as they desired, then the instant runoff would be between B and C, with B winning with 55% of votes.
If a subset of C voters instead strategically vote ACB (6%), this would change the runoff to be between A & C, with C winning 60%.
These are post facto strategies though. You can only implement that strategy if you can guarantee all of that information. Which you can only do after the election.
The first problem is that polling is an estimate. If you are wrong by a couple of percentage points, the strategy fails. If the results come back 16 (BAC), 16 (BCA), 23 (ABC), 39 (CBA), 6 (ACB), B now has 32 first votes and A only has 29.
Next is getting the right number of people to comply. You could easily just mess it up and have either not enough or too many people cast the strategic ballot. If only 4% or less vote ACB, the plan doesn't work. If 11% or more vote ACB, A wins.
In the end, strategic voting is a bit like voter fraud, talked about way more than is actually done. And implied to be a much bigger problem than it ever could be.
Because the relevant fact here isn't that some CBA voters put A at the front (ACB). It's that they moved B from 2nd to 3rd. So of course, that lessens support for B, so B no longer wins.
People seem to present this as a flaw, when it's reflecting actual changes in voting. And this is basically impossible to do so strategically, because nobody has this level of accurate detail prior to the election.
(strategies exist for ALL voting systems. But not all strategies are equally as bad)
