Is this an established phrase?
It would’ve guaranteed that he never again ate alone in Washington.
Does to eat alone have idiomatic usage? Would like to see some established reference attesting to its meaning and usage. The context of the article having this sentence suggests that to eat alone means "to have no followers."
I wouldn't call this an idiomatic expression, but I've heard that phrase never again eat alone used to mean this person is so popular that they can't even eat a meal without people wanting to be with them.