Baumgarten gathers Jewish sources and what they might reveal about Pharisaic practice of and reputation for trading in religious matters (esp. knowing the future). I was particularly impressed to read his intention to move outward from Josephus "to other ancient Jewish sources, notably the New Testament and Qumran" (85; my emphasis), as part of his analysis. First, the identification of the texts of the New Testament as "Jewish sources" (rather than, perhaps, anti-Jewish sources), and second, the realization that their relation to Second Temple Judaism is analogous to the DSS represent appropriate adjustments in our approach to the New Testament at least and perhaps all of first-century CE Christian texts.
But then when Baumgarten turns to consider Matt 12.22–9 (the Beelzebul controversy) and Jesus' interaction with Pharisaic opponents, he aligns Matthew alongside other written texts (and nonextant texts at that!) rather than positioning the evangelist within the world of interaction among Second-Temple Jews. When Jesus asks the Pharisees, "by whom do your own people drive [the demons] out?" (Matt 12.27), Baugarten says, "This passage suggests that the author of the Gospel of Matthew had access to a source that attributed to the Pharisees the ability to exorcise demons" (91; my emphasis).
Why does this passage suggest anything about the sources to which Matthew had access?! Why are we so uncomfortable with the notion that the evangelists (and other tradents of the early Jesus tradition) were themselves experienced participants in the world they inhabited, including their experience reading, performing, enacting, recalling, celebrating, transmitting, and teaching from the stories from and about the sacred scriptures and Jesus of Nazareth?
Most importantly, even if Baumgarten's heavily text-conversant model of the ancient world were appropriate, nothing about Matthew's text would actually suggest a source attributing exorcistic prowess to the Pharisees. As Baumgarten notes (253, n. 49), the Lukan parallel to this pericope (Luke 11.14–22) handles the identity of Jesus' opponents differently but contains the same question, "by whom do your own people drive them out?" Again, on the presumption that we should analyze the evidence in terms of written sources and textual manipulation, the most we could say is that Matthew appears to have had access to a source that attributed exorcistic abilities to Jesus' opponents, and someone—whether Matthew himself, Matthew's source, or someone else we cannot know—thought it made sense to attribute these abilities to Pharisees.
Of course, I don't see any justification for the immediate appeal to sources and especially to the view that, even if written sources are found behind our texts, our texts generate meaning vis-à-vis their sources. I realize the question of how an author manipulates his or her sources sheds light on their own writings, but in the hand of redaction critics comparative analysis has tyrannized any attempt to understand the gospels as autonomous expressions of the Jesus tradition.