In Massachusetts, a respected national leader once (4)

I believe the answer is:

tsar

I'm a little stuck... Click here to teach me more about this clue!

'national leader once' is the definition.
I can't tell whether this definition defines the answer.

'in massachusetts a respected' is the wordplay.
'in' says the answer is hidden in the clue.
'TSAR' is hidden within 'massachusetts a respected'.

Can you help me to learn more?

(Other definitions for tsar that I've seen before include "Nicholas II, say" , "Old Russian ruler" , "Supremo" , "Title of Russian emperor" , "Old leader" .)

I've seen this clue in The Times.

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