the phrase "in the back"
It’s a fear that’s in the back of many of their minds.
What is "in the back of their minds"?

Question

the phrase "in the back"
It’s a fear that’s in the back of many of their minds.
 What is "in the back of their minds"?

Answer

'In the back of ones mind' is an idiom meaning:  if a thought that worries you is at the back of your mind, it is always in your mind although you do not spend time thinking about it.