. >> reporter: now, meet 23-year- old anlin wang.refers green party candidate jill stein. >> her platform stands for more of the direction i would like to see u.s. politics go in. >> reporter: any third party whose candidate gets 5% of the national popular vote qualifies for federal funding. but wang lives in the battleground state of pennsylvania, and he worries a vote for stein instead of clinton could help donald trump win his state. >> because i live in pennsylvania rather than one of those safe states, right, like, there is an exponentially greater chance that my vote could be the one that makes that difference. >> reporter: anlin wang and sadiq khan had never met before, but they are trying to solve each other's dilemmas by using a strategy called vote swapping. here's how it works: on one side, you have a voter in a closely-fought battleground state like pennsylvania who supports a third party candidate-- in this case, green party candidate jill stein; on the other side, you have a voter who lives in a "safe" state like new je