As a Gary Johnson supporter myself, I freely admit that he has some extreme policies that can turn off a lot of voters. But what really frustrates me is how many people I've heard from that do prefer him but are afraid to vote for him because of the spoiler effect.

I keep (wishful thinking) envisioning a scenario where he gets just enough votes that all of a sudden everyone on the fence realizes that maybe he could win and joins in, and then he launches ahead

Wishful thinking and politics aside: there's a term for that phenomenon on the tip of my tongue, but I can't quite place it. Can anyone think of one? Where there's a slow growth until you get just enough of something and then it takes off?