Trump is at 3.5/3.7. -- $1 bet on Trump would win you $3.50
DeSantis is at 5.6/6.8 -- $1 on DeSantis wins you $5.60
Then Nicki Haley is next most active, followed by Pence.
If I were to take a flyer, I'd put money on Dan Crenshaw. His market is 80/1000. I bet if you offered to back him at $175 someone might hit you.
Link: https://www.betfair.com/exchange/plus/politics/market/1.178163916