I have least interest in politics. I consider politics a toxic issue. But it sounds like politics betting is interesting. It is better if people will only treat politics as a way to gamble. That is a fun way of looking at it because, to be honest, politics is nothing but a systematic and constitutional game for the elites and their puppets to fight it out for a few positions. So we better treat it like betting on a horse race.
Politics is really like gambling you are betting with the fate of your country and knowing who's getting the edge and who's behind them will give a good advantage if you will going to bet on an actual betting sites, it's still unpredictable since it can also be manipulated by those dark horses behind it, politics doesn't have real assurance indeed but you can call it as gambling whether you place a bet it not.
Taking gambling in its broader sense, politics is indeed gambling. The only difference perhaps is that, with politics, the stakes are too high. The future of the country, the welfare of the people, the whole national economy, etc are what is at stake.
But I think the betting sites find it a little bit awkward. This must be the reason why politics betting is not found in most, if not all, of the major betting sites. On the other hand, I assume there will be a huge inflow of bets with politics. Everybody is somehow involved in it. Moreover, many supporters of political candidates do not easily change views. Most stick to their candidates all the way out.