Trump’s endorsement of Catalina Lauf on August 13 has sharply shifted trader consensus in the crowded August 18 Republican primary for Florida’s open 19th congressional seat, previously held by Byron Donalds. The former Trump administration official now leads at 81.5% implied probability, ahead of local businessman Jim Schwartzel at 11.8%. Earlier polling showed the pair competitive in the high teens with many undecided voters. Other candidates including Jim Oberweis, Madison Cawthorn, and lower-polling entrants trail significantly. The endorsement, combined with additional backing from Florida Republican lawmakers, has consolidated support for Lauf in the heavily Republican district, while Schwartzel retains some local business and organizational ties. The primary outcome will determine the nominee in a district Trump carried by wide margins.