Do atheists and agnostics tend to be liberal? I can see some being conservative but I have a hard time imagining any extreme right wing atheists.
Right wing is a political term. In the past there have been believers and skeptics on both political sides of the fence. One day there may be an atheist in our highest office. He could be left or right wing. I do think we should stand together on separation of church and state.
There are a (very) few right wing atheists.
However atheists are not by nature liberal or conservative. They are by nature people who based their ideologies and live their lives based on facts. It happens that liberals also based their ideologies based on facts. So atheist ideologies most often align with liberals.
However, just because they follow parallel lines of reasoning does not mean they in agreement in all areas.
I would agree with that. I can see the moderate conservative could be an athiest but any farther to the right tends to go along with a heavily Christian ideology. Much of the right wing platform is underpinned by Christian beliefs like anti-choice, anti-lgbt, pro prayer, anti-feminist, etc.
I'd say Ayn Rand was about as conservative as you can get and still be an atheist...