In any case, of course Merchant of Venice is an Anti-Semitic play.
Of course it isn't. The only ones who twisted Merchant into an antisemitic piece were the nazis. Naturally one can, like the nazis, always "read into" a play one's own opinion but the decent stagings of the Merchant who are true to the text acknowledge the complexity of Shylock who is not an antisemitic character at all. Gee, over here the seminal portrayal of the character is the one by Kortner, a Jew. He'd hardly have staged the piece or played the main character if it were antisemitic.
You are aware, I hope, that the Nazis did not invent anti-Semitism. In fact, throughout Shakespeare's life, and for centuries surrounding it, Jews were not even permitted to enter Great Britain. It was illegal to be a Jew and to enter the country. Shakespeare very likely never even met a Jew. All he knew about Jews was what people on the street talked about, and what they talked about were all the most horrific Jewish stereotypes you can imagine. In fact, one of the most popular plays at the time in England was The Jew of Malta, by Marlowe, a play with a horrible, villainous Jew at the centre of it. So, for you to suggest that Shakespeare, in the centre of a completely anti-Semitic time and place, was somehow a beacon of liberality and understanding toward a race of people he had never even met, is just a little far-fetched.
Next, you misread your history if you believe it to be a tragedy. It was originally conceived as a comedy. It's actual title is "The Comical History of the Merchant of Venice Or Otherwise Called The Jew of Venice." Shylock is not the tragic hero or victim of the play, but the comical villain. At the end of this comedy, the Christians win, get married, and have an entire act and a half to themselves to sit around underneath the moonlight (with Shylock's stolen and converted daughter with them) discussing love and romance and how sweet life is, just like the last act of any number of Shakespeare's other comedies. In this comedy, the good guys, the Christians, win, and the ridiculous and clownish Shylock, the vicious Jew, is essentially destroyed, much to the happiness of all the other characters, his own daughter, and to the contemporary audience at the time, none of whom had the least bit of knowledge of or sympathy for Jews, never having met any, most likely. This play was treated as a comedy, played as a comedy, and written about as a comedy, all the way through the next few centuries. If you don't believe me, read historical theatre criticism. The idea of Shylock being someone we're supposed to feel sorry for is a fairly new concept.
It was only with the 20th century that critics began to try to re-interpret the play as a tragedy. And it does indeed work very well as a tragedy (I highly recommend the Al Pacino version, an excellent and sympathetic performance.) But that is because it is the only way to make the play palatable to a modern audience. The problem is, to a modern audience, the play just isn't funny. All the jokes come from making fun of Shylock's Jewishness (go back and reread the play - all their attacks on him have to do with his Jewishness, and his perceived Jewish characteristics.) As a result, it no longer works as a comedy, for obvious reasons. As a tragedy, however, Shylock becomes one of the best tragic characters in English literature.
But that was by no means the original intention. We have to keep that in mind when talking about the play. Yes, of course the character is complex. So is Richard III. So is Iago. All his villains are complex, and even, to a certain extent, sympathetic. But they're still villains.