Being a former liberal Democrat, I can vouch for much of this. The general ethos of the leftist mind necessitates that you must resist restraining (conservative) impulses. Logic and reason are restraining impulses. Since modern liberalism is primarily a state of unrestrained emotional turbulence, the liberal must find reasons for excusing his most base emotional instincts and instead embrace the "liberation" that comes from not being able to summon reason to control your impulses. Many consequently fall prey to the tempting natural impulse of letting emotion override logic and reason. The liberal creed dictates that feelings are more important than anything, and that they shall hold court over reason.