I'm in the middle of The Crusades by Jonathan Riley-Smith: it's a general survey, admittedly, but it's a good one, and I haven't read much on Crusading specifically.
The movement did persist an awfully long time. Some things that brought it down:
Persistent failures on the part of the crusaders
The rise of nation states
The Reformation
Humanism
Those, anyway, are some of the internal forces within Western Europe that helped bring the movement down. Those are the forces that would need to be addressed for Crusading to survive. If the Mongols made more advances into Western Europe that could disrupt things enough that crusading remains a strong motivator.
I know there have been AH attempts to make the Latin states in the Eastern Mediterranean survive longer. That's not quite the same as the idea of crusading, but a Kingdom of Jerusalem that endures into the 1600s or beyond could continue to attract "crusaders" from the West.
And I understand the tension on this thread. What the crusaders did was bad, sure, but there's something about the movement that's undeniably... cool. Or at least, there are aspects of it that touch the imagination in certain ways - hence all the romanticism surrounding it. The whole idea of knights sailing to the Middle East to capture cities in the name of God and His relics is certainly ridicuous to us, but they were dead serious about it. I guess it's the theme of fighting for your convictions that people find fascinating, even if those convictions appear so very misguided to us.