Final answer:
George W. Bush won the 2000 presidential election in Florida by 543 votes, securing the presidency.
Step-by-step explanation:
The candidate who won Florida by only 543 total votes in the 2000 presidential election was George W. Bush. The election between George W. Bush and Al Gore was extremely close, with Florida being the deciding state. Initially, Bush had a small lead, but a recount was ordered. However, the recount was halted by a Supreme Court decision, and Bush was declared the winner, ultimately securing the presidency.