Well, unless the house is collecting a huge rake (like at the horse track), there should be a sucker and a sharp with each bet.
The whole idea of advantage gambling is to get odds at a better percentage than the true odds. When you count cards in blackjack, you can switch a .5% house edge to a 1%-2% player edge, depending upon how aggressive your bet spread.
In sports betting, you are essentially looking for mispriced lines that (in a straight bet) would let you win over 52.5% of the time.
So, if the political betting markets become mispriced because suckers are laying money on Trump, that means there is a sharp-side bet for Kamala. There really shouldn't be suckers on both sides of the line -- particularly in a trading market like polymarket. One side is the sucker side and one side is the sharp side.
If betting markets are completely irrational, then there is a significant financial advantage to be obtained. I am just not as convinced as lawtig that betting markets are completely irrational. So, I essentially proposed putting your money where your mouth is. If someone thinks the markets are way out of whack, they should pound them.
Now, when heelyeah raised this point earlier this year, I suggested that there are lots of reasons not to tie up your excess cash in futures bets that won't payoff for 9 months. That argument is a lot less compelling now that we are less than 100 days from a payoff.