I see "blind sheep" as meaning more that someone follows blindly. Without being privy to your conversation with her, and the questions and responses, I can't say that she was doing something blindly, although I don't get that impression since she wanted to ask you questions and understand why you voted the way you did. "Blind sheep" usually means that someone is a follower with no real opinion of their own or understanding of that which they are following. I don't get that impression of your friend.

But you're right that she lacked respect for your boundaries and that should be a red flag to you. Ask yourself, why do YOU want to continue a friendship with someone who can't respect your boundaries?

I suspect that if had not been politics, your friendship may have been in jeopardy because of something else in the future, because of her lack of respect for your boundaries.

I said I have few friends who don't share my political beliefs, but that's not true. I actually have many friends who I have no clue where they stand politically and I don't care, because that's not what we share together and I have no desire to discuss politics with them.

You have every right to say to a person, I don't want to discuss politics and stand by that. If they won't change the subject, then say, well, let's chat another time, or say, well, it was nice seeing you but I can't chat about this topic right now, and leave. Don't let people make your boundaries a doormat.