Like the revolutionaries in France, Russia, and elsewhere, they appeal to the masses' utopian desire for égalité--equity & fairness--all the while excepting & exempting themselves from the plans and rules they outline for everyone else.
In the extreme, they give the hoi polloi communism or in the intermediate, socialized medicine, etc., to sate the class warfare they (revolutionary leaders in the former, John Edwards with his "two Americas" or Barbara Boxer with her "well-dressed" critique of town hall participants, in the latter) themselves started.
This impulse, this pursuit of égalité has caused more death and destruction than any other single ideological movement in world history.
Between Stalin's Russia, Mao's China, the Khmer Rouge and many, many more, literally hundreds of millions of people have either been killed outright or starved and died as a result of the programs & policies emanating from égalité.
Mind you, I'm not opposed to the idea that all men (& women) ought to be viewed equally before the law. This, I believe, is the idea expressed in the Declaration of Independence.
What I have a problem with is the leveling philosophy that views equality as an end unto itself. Most often, this philosophy is expressed by people who do not subject themselves (see the Sidwell Liberals from last week, "limousine liberals," and anyone else in history or contemporary times who opts out of the programs they establish for everyone else) to the practical ramifications of their social reordering.
In the USSR, China, Cuba, etc., they had/have their private doctors, dachas, and other special privileges, while the people around them lead equally sucky lives.
This then is the end result when égalité is your highest order principle: No one is lifted up, because of the disincentive to improve one's lot in life. Rather, in order to achieve equality or equity, others are pulled down, their wealth redistributed, and their liberty, along with that of everyone else, limited.
If you have tips, questions, comments or suggestions, email me at firstname.lastname@example.org.