All liberal Western democracies feature mixed economies. Just take a look at government spending over GDP ratios.
I am not an anti-capitalist precisely because the problem cannot be captured via this one-dimensional "how capitalist and how socialist should our nation be?" categorization. Take the bank bail-out, it was socialism. Sure, socialism for the rich, lemon socialism, only losses have been socialized, but it was nonetheless socialism. What happened a few years ago in Iraq has also been socialism, for Halliburton and so on. Right-wingers might bitch about socialism but they gladly apply it when it benefits themselves.
China, the country which is capitalist and communist at the same time (of course right-wingers call it communist while left-wingers call it capitalist but de facto it is both at the same time), also neatly illustrates why this categorization game is useless.
The problem is not capitalism but the increase of political power of capital and our lackadaisical response ... especially on the left. The enemy are Third Way social democrats (being myself to some degree also a conservative social democrat I am here basically saying that I am myself the enemy which is nothing paradoxical; unless one is a fascist who can play the antisemitic game of blaming an outsider the enemy is always oneself) whose historic crime has been to give legitimacy to the Thatcher and Reagan revolutions.
I don't remember where, he writes too much, but Joe Stiglitz neatly pointed out that in a hypothetical world without boundaries the political power of capital relative to labour would decrease, if just for tax incidence reasons (if you tax capital today all that happens is that it leaves the country such that the net rate of return remains equal but with less capital the workers are of course less productive, i.e. capital taxation mainly leads to wage decreases because capital is internationally far more flexible than labour).