They have a common because they all share a location which can be implemented on maps
The crusaders were trying to promote Christianity. They did this not by converting, but mainly by fighting others (infidels). During the crusades many people were killed. The crusaders were hypocrites because they believed that is is acceptable to kill in the name of a religion that explicitly says "Thou shallt not kill".
The incorporation of the bill of rights is a doctrine that defends that The Bill of Rights should be applicable and respected by the states of the US.
Initially, the Supreme Court was strict on this matter and the common understanding was that the Bill of Rights should only be respected and followed by the Federal Government - you can see it on Barron vs Baltimore case. After the abolition of slavery and the post-civil war era many rights were granted to people and over time the incorporation doctrine gained strength.
