The roots of such bizarre hero worship are complex, but for all its apparent incompatibility with a Left which claims to promote freedom, equality and prosperity, there is a linking thread. Whether it be Robespierre, Stalin, Castro or al-Qaradawi, all their actions stem from the same certainty that the broader Left holds: that the ends it seeks are so incontrovertibly proper that the means are justified for the greater good.I don't agree with Stephen that this explanation works. Everybody has to engage in means-ends reasoning, and we all think that the end justifies the means sometimes - or, to put it another way, we think that some benefits justify some costs, some end results justify the ways of bringing them about. If no end ever justified the means chosen to achieve it, this would rule out not just high taxes, but taxes, period - and to provide for policing and street-lighting as well as schools and hospitals. The problem isn't in thinking that some ends justify the use of some means; it's a truism that this is so. The problem comes rather from (among other things) disregarding certain very important moral boundaries or constraints - people's most fundamental rights, their vital interests - in the name of ends that are distant, uncertain and often highly speculative.
It might not be a very deep philosophical explanation, but it works even for relatively prosaic obsessions of the Left such as high taxes. Because it is, to most of the Left, self-evident that only the State should run schools and hospitals, so it is perfectly proper to take people's money to finance it. The ends make the means entirely justified.
The explanation for why some on the left look up to or make excuses for tyrants is, as Stephen himself says (though without following up on the thought), complex. I won't here try to deal with the several reasons for it. But one historically powerful reason has been the temptation on the left to allow anti-capitalist and anti-imperialist commitments to trump democratic and human rights principles. This is relevant to the Cuban case: many who admire the achievements of the Cuban revolution in health care, education, literacy, prefer not to dwell on the fact that the country is a dictatorship. It's an old and damaging temptation. Emphasizing, quite properly, social and economic conditions and the attempt to improve the lives of working people, it fudges issues of democracy and of indispensable liberties, as if these might be merely optional or unimportant.