In the Ramayana, Vali had the boon that in a duel, he would acquire half the strength of his opponent, which is why Rama was constrained to kill him by deception. He had to shoot an arrow from behind while VAli was duelling with Sugreeva.
In First Past the Post election systems, adversaries who are in the first or second place tend to benefit from Vali’s boon. First and second place parties are alternatives to each other. Voters dissatisfied with the incumbent will strategically vote for the second party as it is best placed to displace the incumbent. They will do this even if they do not like the second party all that much. Some of them may in fact prefer a third party, but choose not to act on the preference as they don’t want their vote to go waste.
There are many corollaries that flow from this.
Second place parties are weaker than they appear
The first corollary of Vali’s boon is that parties in first and second place can punch above their weight for many election cycles. A party may be getting structurally weaker. Its organization may be suffering atrophy and voters may be getting increasingly dissatisfied with it, but as long as it stays at or above second place, it can come back to power. Now, power is an aphrodisiac that can hide the fact you can’t get it up on your own. So a party that is in power can hide many of its weaknesses till they overwhelm it and push it to third place. The optimistic way of looking at it is that as long as you are in the second place, you get a chance to work on your structural weakness.
If you drop to third place, you drop further
When a party drops to third place, the drop comes with a momentum that has the power to push you to oblivion. This is due to a preference cascade. If voters have been voting for you only because each one thinks that the others support you wholeheartedly, then the drop to third place will give them the message that that is not the case. Those who preferred a third party, but voted for you for strategic reasons no longer have to falsify their preference.
Parties in third place can be stronger than they appear
Third place parties are likely to be stronger than they appear. This does not apply in all cases. Obviously, a party on its way down that falls to the third place is likely to be weak and get weaker. But a new third party or a party that has been in existence for long and is trying to break through can have a lot of hidden support that doesn’t translate into votes, as voters have been strategically voting for the party likely to win.
A party needs something extra to sustain third place
Unlike parties in the first and second places that can feed off each others’ strengths, a party in the third place will not sustain for long unless there is something else to keep it alive. That is because after a few election cycles, voters who support your point of view will weary of a party that has no chance of winning, as will leaders of your party. So if a party has sustained for long in third place, we must ask what that “something else” is. This can be a strong and committed ideological community or a strong caste identity. Or it can be a national party who happens to be a bit player in this state, and the strong national unit is propping it up. Or perhaps the state has a history of coalition governments, in which case being a third party is positively lucrative.
Vali and Sugreeva tend to look alike
Parties that have been in third place for long face a dilemma. There is usually a reason they have sustained for so long and there is also a reason they have not broken through for so long. Very often, the two are closely related. There may be a subset of voters whose preferences differ starkly from the majority. Breaking through to the top 2 involves appealing to the larger constituency, but this will piss off the dedicated minority as the appeal may go against, or at least de-prioritize their preferences. Likewise, you may have a dedicated set of leaders who have steered your party during its third place phase with little prospect of reward. You don't want to let them down. But the reason the party hasn't broken through may be due to the limitations of those same leaders. So you have to figure out how to side-line your dedicated voters and leaders without alienating them.
In the Ramayana, Rama couldn't slay Vali the first time as he and Sugreeva looked alike. Sugreeva had to refight the duel with only a cosmetic change to differentiate himself. This tells us something about how First Past the Post systems work.
Caveats
Now, the caveats. Obviously, this post has been written in the aftermath of the Karnataka elections, so please go ahead and use this framework to analyse the results. When you do so, keep in mind that this is a framework, not a formula. You can’t plug in the values and get an analytical result at the other end. Vali’s boon is a framework to guide how to think about election results.
Some of the conclusions are straightforward - The INC has obviously benefited from Vali’s boon here, and its structural weakness hasn’t gone away, and we must not exaggerate the extent of its success. Others are not so straightforward. Is the JDS a third place party because it always comes third in the assembly elections, or is it a second or first place party in the constituencies it has a major presence? The answer to this depends on how the voters in question think of it - do they think at state-level or at the constituency level. Similarly, has Karnataka become a two-party state? We mustn’t draw that conclusion from the results of one election. These unknowns are what make this a framework rather than a formula.