Third parties or stay home.
Again, if they stay home that doesn’t reduce the need for 100% vote... third party won’t get 15% of the vote... you are talking close to Perot 1992 numbers at that rate.. and they won’t tally that high.
Maybe can stretch them out to 10% if you are very very generous.. but realistically I expect third party votes will be in the 7ish range... that leaves 5-8% unaccounted in your numbers.