Polls tell you who people say they are voting for. They include margins of error for an abundance of reasons.
Betting markets can tell you who people think will win. However, Polymarket has been heavily skewed by a $15 million bet from a user named Fredi999 who allegedly has placed multiple other bets on other accounts that total $46 million.
"Business Insider compiled the trading activity of the four accounts and found that two of them, Fredi9999 and Theo4, together have placed more than 2,500 bets in the past 24 hours.Theo4 has placed as many as 71 bets per minute, suggesting that the betting activity could be automated."
People (the bulk of bettors) think it's around 50/50... this "person's" bets have skewed the numbers to 60/40.
And again, these bettors are not Americans. They are overseas. So betting markets do not measure American sentiment through money wagered.