I think you have to sign into academia.edu before you can download. But the idea is that academics have to analyze the issues and come to terms with them fairly and honestly, and not pay attention to what the political implications of their statements are.
An example of this would be criticisms of Thomas Nagel. Nagel is a non-theist who develops a lot of the arguments against naturalistic materialism that I do. But he thinks you can accept the arguments supporting the idea that reason and "the mental" is fundamental to the universe without becoming a theist. In the process he is critical of the overuse of evolutionary biology to explain everything. Now, I can understand why many secularists think that he's mistaken, that materialistic naturalism doesn't have quite the severe problems Nagel thinks they do. But, on top of this comes strong message that he's giving aid and comfort to religious believers and even (gasp!) intelligent design advocates, and they virtually imply that if that is what he really thinks he ought to shut up about it because of the bad political implications of making his case. After all, you don't want someone giving ammo to those "armies of the night." When people criticize them for heresy hunting, they just reply by saying "We're just criticize arguments we don't accept. Shouldn't all ideas be open to criticism?" But no, you aren't just doing that, you're saying his ideas lead to "mischief" and one philosopher, perhaps jokingly, said that his books should be put on a modern secular version of the Index of Forbidden Books.
To them, I want to say, cut the political correctness and follow the argument where it leads.
The paper argues that the political involvement of philosophers may lead them to not give fair consideration to positions that could be used to support their political opponents. I am inclined to agree.