I have the same feelings about this as I do about all of the attempts to organize atheists, how much common ground can be expected from a group of people organized around something that they don't believe in?
Just look at the range of diverse views on this discussion board.
In my own family of atheists my father is a far right political conservative while my brother is a west coast liberal. I believe that having to listen to my brother and my father argue over politics is what pushed me away from ideology and into being a radical moderate. I saw the weaknesses in many of their respective arguments and more importantly for me in how having an ideology limits your thinking.
Atheists can't even make a very good argument as the basis for a civil rights movement. I possibly have been discriminated against because I am an atheist, but I am not aware of any such occasion. Socially I suffered more in the 1960's through the 1980's because I was either in the military or because I had been in the military, than I did because I am an atheist.
I don't put any value on a person being an atheist when I evaluate people, any more than I would consider their firmly held conviction that there is no Santa Claus or.that there are no unicorns.
Excuse the personalizations in this post. I have been wallowing in some bad family news since election day, and no, it doesn't have anything to do with Trump.