Also, the politician generally seeks to cash out by selling to the current electorate, leaving the outcome of the actual vote long after many of those involved in the original debate are dead somewhat moot. The rewards are for what the electorate think the long term outcome of your policy will be at the time you sell it, not what it actually is.
Take an issue many electorates have strong opinions which have massively changed over the last 40 years like gay rights.
Go back to 1981 and a politician would not have struggled to sell futures on draconian restrictions on gay rights. Many people would have bought in the belief such policy would prove essential to save civilization, or at least sensible in the context of worrying reports about a new disease. Sure, those futures trade at a massive discount by the early 2000s and don't pay out in 2021, which means the citizens who bought them (or more likely their inheritors, whose view on the issue is very different...) lose on the bet, but the politician would have been significantly enriched at the time despite the future's verdict being that it was very bad policy.
Take an issue many electorates have strong opinions which have massively changed over the last 40 years like gay rights.
Go back to 1981 and a politician would not have struggled to sell futures on draconian restrictions on gay rights. Many people would have bought in the belief such policy would prove essential to save civilization, or at least sensible in the context of worrying reports about a new disease. Sure, those futures trade at a massive discount by the early 2000s and don't pay out in 2021, which means the citizens who bought them (or more likely their inheritors, whose view on the issue is very different...) lose on the bet, but the politician would have been significantly enriched at the time despite the future's verdict being that it was very bad policy.