It's pretty rare, even in politics, for a reasonable, respectful, and constructive comment to be downvoted enough to be hidden. If your comments are frequently hidden, you may want to reconsider your tact in replying to people.
Not all comments that ought to be hidden are violations of our terms of service. Some comments are just rude, uninformed, or off topic, but not really violations. Hidden comments are also a way for full-on violations to be hidden more frequently since mods cannot instantly moderate every comment.