Question

Why might Nicodemus have questioned whether or not Jesus was the Messiah? because Jesus did not fight the Roman government

because Jesus did not claim to be the Messiah
because Jesus had so few followers
because the prophecies in the Scriptures were not very exact

Answer 1

I think the answer to your question is because Jesus had such few followers.

Answer 2

The answer should be "because Jesus did not fight the Roman government."