MongoDB 2 node cluster

I am trying to understand the implications of setting up a 2 node MongoDB cluster with the following configuration (Documentation does say a minimum of 3 nodes is required). MongoDB Version is 3.2. If I configure both nodes with "arbiterOnly": false, and set Node1 with Priority: 2 and Node2 with Priority: 1, in case Node1 goes down, won't Node2 take over? Why not?