Here is what he says regarding the move in scholarship to emphasize Paul's Jewishness:
I hope to post more on this essay in days to come.
This rediscovery of the full Jewishness of Paul was paralleled by the earlier rediscovery of the Jewishness of Jesus, led too by Jewish scholars, but now commonplace among the Gentile scholars. ....The entire trend is salutary in that it gives heed to the fully Jewish character of our New Testament and of the Christian faith of its authors. But the subject is often pursued in such a manner as to ignore or downplay the discontinuities caused by the dramatic newness of Christianity itself. Contrary to the frequently heard claim, the Christianity of the New Testament is not simply reformed Judaism or a Judaism applied to Gentiles. The tensions and discontinuities between Judaism and Christianity should not be swept under the carpet even for the good motive of wanting to avoid anti-Semitism, as important as that is.
Yes, Paul is fully Jewish and his Christianity is characterized by great continuities with Judaism. At the same time, however, a close reading of Paul...points also to striking discontinuities which must not be minimized. The issues are complex and a fairness to all the data necessitates complex conclusions. But to be stressed here is that if we disallow the complexity, and in reductionist fashion explain Paul solely in terms of continuity, we will misrepresent Paul.