Carlos Alberto Montaner's commentary published on Real Clear Politics has two extremely succinct summary sentences that tersely define modern leftist ideology.
"After the fall of the Berlin Wall and the disappearance of the Soviet Union, the Left everywhere stopped offering options for governance or serious theories about development and equity and sought refuge in protest."
"The Left today is nothing but circus and street violence."
Ladies and gentlemen... welcome to Clinton & Kerry's three ring big top. Today, as yesterday, we will astound you, we will amaze you, with raging wild beasts, busloads of clowns, magic words that never actually do anything, and lots and lots of poop! So step right up (but, watch where you step) and prepare yourselves for the entertainment extravaganza of a lifetime.
(H.T. to John Ray of Dissecting Leftism, or A Western Mind, or Greenie Watch, or...)