What percentage do politicians have to have in order to win without a run off?

Answer 1

In every state except Louisiana, they simply have to be the leading candidate (a plurality) rather than having a majority of the votes. In Louisiana, candidates need one vote over 50% to avoid a runoff election.

Answer 2

In order for a cantidate to win an election, they must win by a margin greater than 1% anything less, and the losing cantidate can request a recount of the ballots (remember pregnant, dimpled, and dangling chads?)

Answer 3

51% majority