After reading so many misuses of some specific words this morning describing agreement, I thought it might be handy to provide a few definitions.
Also unanimous. Unanimity means that everybody agrees with something. It’s rare.
Consensus means “general agreement”. As a rule of thumb you need at least two-thirds of the participants to agree before you can start calling something a consensus.
One half plus one.
When there are more than two opinions being expressed (including “no opinion”), whichever opinion has the most adherents is the plurality opinion.
Fewer than one half plus one.
It is not true that there’s a consensus that President Obama is the worst president of the post-war period. One poll has found that it is a plurality opinion.