Muslims hate western culture. All of it. Islam is an imperial "religion" that encourages spreading of the belief by sword, fire, rape, loot, lies, and deciet. Further it is the religion of hydraulic empires where the most violent will always rise to the top. All Arabized cultures, from Pakistan to Mexico and Central America show the same problems.
Liberals hate the morals and traditions of western culture. They think their Nirvana is just around the corner but they are blocked by people that are unwilling to surrender their rights. They blame Christians and Jews for stopping them.
The liberals throw open the gates in the full knowledge they are letting barbarians into the country. The intent is to buy off these barbarians to put the liberals permanantly in power while the barbarians attack the lefts political enemies and keep the population stirred up enough to justify attacks against rights and liberties. It never works though. Once the barbarians are in, they demand more and more until the host society collapses and then they sieze control of their own areas.