Why do left wingers hate america so much but love dictators like Castro and Hugo Chavez?

I am a pretty smart guy and I just dont get this. Why do they hate America where we have freedom and love oppresive regimes like Cuba and now Venezuela. I mean I recall hollywood actors saying that Fidel was the greatest guy around or something like that. If they hate it here so much, why dont they move to some place like Cuba(some have threatened that, but not followed throught) If you have any ideas about this, please let me know. Thanks.