Why do you think economics is the only real area where the left is so supressed? Do you think it is because economcis deals with the bottom line for the capitalists: money?
You say that in other countries, including other capitalist countries, it is quite normal for Marxists theory to be taught at universities. I am from Australia and I must say that Marxist theory is tolerated in some fields such as literature, philosophy, history, sociology, etc. In Australia much historical research by the left on the 19th century killings and maltreatment of aboriginal people is seen as mainstream and accepted by the general public.
I have never been to the USA, but from meeting many American professors at conferences and reading journal papers in my field- I have also to say that in the humanities such as history and philosophy, most academic staff are left of center and Marxist viewpoints are respected. To be honest, in some areas of study such as sociology or literature, the whole faculty is left wing you are the odd one out if you are conservative.
In media studies Marxist critical theories, such as the Frankfurt school, have become mainstream; and in art left wing painters such as Picasso hang on everyone's walls.
BUT when it comes to economics it is a completely different story, even in Australia or Western Europe Marxist economics is a big no no. In just about every country neoclassical economics is the orthodoxy and religious creed. Economics has shifted so far to the right that in Australia even Keynesians such as Steven Keen are seen as dangerous radical pinko commies. Open up any economics text book in Australia and it is pure neoclassical stuff, nothing heterodox at all. The first year(freshman) economics textbook at my university had only two pages on socialism and all that was said was that it was a failure and it represented "the tragedy of the commons on a grande scale". As far as I know there are some heterodox economics options at the university of Sydney, but at all the other universities across the country there is nothing but neoclassical economics on offer.
It is not only in academia where the left are snobbed, but media outlets also refuse to show the lefts opinion on economic matters. Business sections of news and talk shows never show a left of center economists or commentator.
Like I said, Marxist and left wing ideas are part of our society, art and education system and they are tolerated' yet Marxist economics (or for that matter any form of economics that is not neoclassical) is seen as taboo. Why do you think economics is the only real area where the left is so suppressed? Do you think it is because economics deals with the bottom line for the capitalists: money.
While I think you do somewhat overstate the case, your basic point is valid and important. Marxian ideas in economics are far less acceptable and far more rarely encountered than they are in many bother disciplines etc. Let me respond first by noting that this reflects the generally uneven development of paradigms in different fields. For example, 30 years ago, the relative presence and absence of Marxian work in the disciplines would have shown us a very different pattern from the one we see and you well describe today. Moreover, today too the pattern is changing. Left ideas in economics are surging - due largely to the current crisis - and are more acceptable now in university but also mass media settings than has been true for at least 30 years. Take a look at this website to see how one Marxian economist's work is getting around the US and beyond over the last 2 years. It is far, far better an environment now than in many, many years, notwithstanding how far we have yet to go.
We are in a 30 year spurt of neo-liberal capital accumulation, stagnant real wages accompanied by rising productivity (together yielding fast rising profits). Capitalists have used their exploding profits to buy and transform politicians and politics into the global neo-liberalism we see everywhere. They not only provoked a massive global crisis in this way (periodic characteristic of capitalism for 250 years) but they are now busy using the crisis itself and mass anger about it to yet further push their agenda of a return to 19th century levels of economic and social inequality. In this context, Marxian criticisms need to be buried, brushed quickly aside, rendered absurd or simply silenced...they are just too out of sync. The dialectical problem, of course, is that the very crushing of unions, leftism, Marxism etc. facilitates the over-reaching, extreme crises, and inequalities that will, in turn, fuel the reaction of a resurgence of the left. That process is already underway in Europe and the US.
I cannot, of course, predict the future and whether or how far that process will go this time. But I am sure that just as Obama's triumphalism has been blown away - just as Bush's before him was - so too will the Tea Party and right wing Republican capitalism's fall before the contradictions of this system. Marxism is the product of capitalism's contradictions. Nothing guarantee's the former's further development and importance that the latter's expansion.