Not a new phenomenon! It happened during the War on Iraq. https://www.nytimes.com/2003/03/02/weekinreview/you-can-bet-...

People will bet on absolutely anything; gambling is as old as time itself.

> Wagering was generally legal under British common law, so long as it did not to lead to immortality or impolity.13 Bets about the outcome of events in war, over the death of political leaders, over court cases, or between voters over election results were illegal on these grounds.14 In the Victorian and Edwardian periods, the British government increasingly attempted to limit gambling, especially among the working classes. The Gaming Act of 1845 made gambling contracts and debts unenforceable in court (but otherwise liberalized what amounts could be wagered); the Betting Houses Act of 1853 outlawed the operation of betting establishments other than private clubs; the Betting Houses Act of 1874 cracked down of the advertisement of wagering; and the Street Betting Act of 1906 made acceptance of wagers in streets and public places illegal.15 Despite the legal uncertainty in the late 19th and early 20th century, the Fleet Street press reported on election wagering at the London Stock Exchange and at Lloyd’s in markets for Parliamentary “majorities.” [^0]

[^0] Rhode, Paul W. “The Long History of Political Betting Markets.” KU School of Business, 2012 March. https://users.wfu.edu/strumpks/papers/Int_Election_Betting_F...