Saying that you can’t consider a source valid if it is “right wing” is literally exactly equivalent to saying “I refuse to listen to anyone who might disagree with me.” Alternatively: if they disagree with me, they are invalid for that reason alone. Self evidently, this is not the creed of any HONEST Liberals.
This website is called “Moderates United”. I consider myself a moderate. I really do. There are people to the right of me who want to bring back institutional racism and sexism (although not very many outside of the very large group of Islamic Scripturalists, who most likely number in the hundreds of millions), and most of the world has fallen off a cliff to the Left of me, believing–as I see it–demonic and deluded things which work to destroy people and societies spiritually, morally and economically.
I’m just trying to say reasonable things, that in a sane world would be uncontroversial.
That, in a sane world, would not NEED to be said.