A high tax, not to mentioned unemployment

English as a Second Language English Vocabulary, Grammar and Idioms
1

A high tax, not to mentioned unemployment, influences votes.
I can not work out with the bold part. How is it modifying “A high tax”?

2

The expression is ‘not to mention’ means the same as ‘without mentioning’. I think the sentence would read better as: High taxes, without mentioning unemployment, influence votes/influence how people vote.

The expression ‘no to mention’ does not modify ‘a high tax’. It is simply an additional factor in assessing how people vote. You could say: Npt only taxes but also unemployment affect the way people vote.

3

Both a high tax and unemployment influence how people vote. But since the role of high tax is very high than unemployment we can say–

A high tax influence how people vote ( without mentioning unemployment.)

am I correct?

4

Both a high tax and unemployment influence how people vote. But since the role of high tax is very high than unemployment we can say–

A high tax influence how people vote ( without mentioning unemployment.)

am I correct?

5

You would have to change it to:
‘A high tax influences how people vote.’
though as has already been mentioned
‘High taxes influence how people vote.’
would sound more natural.
Alternatively,
‘A high rate of tax influences how people vote’
would be okay.