Prolific author and speaker Don (D. A.) Carson, research professor of New Testament at Trinity Evangelical Divinity School in Deerfield, IL and one of the leaders of The Gospel Coalition, has recently released an excellent treatment of the specious form of tolerance operative in the arena of political correctness, in his The Intolerance of Tolerance.  Published by Eerdmans and available here, the book details the change in the definition of tolerance from a willingness to be civil or cordial towards someone who holds views with which you disagree to the view that all views should be tolerated except those which make absolute truth claims. This is a rich discussion of phenomenon and captures in its scope issues like pluralism, relativity, and church/state relations.  Dr. Carson does not leave the subject in the abstract but discusses actual cases of intolerance cloaked in the garb of tolerance.  This book is  must reading for Christians.