Incumbent Republican Brian Mast holds a structural advantage in Florida’s 21st congressional district, where his 2024 reelection by roughly 22 points and the area’s consistent Republican lean anchor trader expectations for a GOP win. The closely matched prices on Person A, Person B, and the 5–15 point Republican margin buckets reflect uncertainty over the precise spread, driven by Democrat James Martin’s narrow primary victory and limited recent polling. Solid Republican ratings from forecasters reinforce the consensus, yet the 7% probability assigned to a Democratic upset highlights the potential for national midterm shifts or turnout surprises to narrow or widen the final result before November 3.