Just to clarify.
To perform a vote/election, you must have a majority of the replica set nodes up an running.
So if the replica set had 4 nodes, and 2 were down, then because a majority of 4 is 3, then 2 isn’t enough. Even though the 2 nodes could decide between them who is most capable to carry on the be the primary, based upon who is most up to date (as mentioned in the video)
If the set had 6 nodes and 3 were down, the majority of 4 is not available, so a new primary couldn’t be picked.
Why is the majority so important for elections, or is the concept of majority for something completely different.