No Republican has ever won the White House without winning Ohio. The last Democrat to win the White House without winning Ohio was John F. Kennedy in 1960. Starting with Lyndon Johnson in 1964, the presidential candidate who won Ohio has also won the presidency. See 2020 primary results
CNN will broadcast a projected winner only after an extensive review of data from a number of sources.
"Flipped seat" denotes a race where the 2020 projected winner is from a different party than the previous winner or incumbent.
Both Maine and Nebraska allow electoral votes to be split. In Maine, two of four electoral votes go to the statewide winner and one electoral vote goes to the winner in each of the two congressional districts. In Nebraska, two of five electoral votes go to the winner of the statewide vote. One electoral vote goes to the winner in each of Nebraska's three congressional districts.