Actually, your own cited statistic supports his thesis.
In fact, 1/3 of all American Jews are married to non-Jews, mostly Christians.
See? That means that 2/3s of all American Jews are married to other Jews. In other words, those who marry other Ashkenazim outnumber the intermarriers by a factor of two to one.
See? That means that 2/3s of all American Jews are married to other Jews. In other words, those who marry other Ashkenazim outnumber the intermarriers by a factor of two to one.
In 1990, the intermarriage rate was 52%.