Did you know that in the primaries for the 1968 election, Vice President Hubert Humphrey did not declare his candidacy until April 27, 1968?
He wound up the eventual nominee.
President Lyndon Johnson withdrew, Robert Kennedy was shot and only entered in March, himself.
Eugene McCarthy had the most popular votes and won the most states.
Humphrey won zero states.
But Humphrey got the most votes at the convention and was nominated as the Democratic candidate.
Can you imagine the major candidates not entering until after the first primary?
Anyway, a lot can happen between now and when the voting starts.