so my voting might be like
1) Johnson
2) Romney
so we calculate all the #1 and see who is the top 2 contenders. then recount the highest vote to those 2. in my case if the runoff was between Johnson and Romney then my vote goes to Johnson. but if the runoff is between Romney and Obama then my vote goes to Romney.
更新1:
runoff - i am not talking about a runoff - just a recount (computers do it in seconds) of your existing votes