This makes zero sense whatsoever. Either she assumed all Muslims are raging, foaming-at-the-mouth anti-Semites who would melt at the sight of a Magen David or she's just one of those AIPAC-ers who thinks Israel is the 51st and most important state in the US.
That paragraph struck me as well. Really embarrassing, but let's be honest: her attitudes don't just represent Austin, and frankly it's not just in the United States. As I recall it wasn't long ago that most posters on this forum were extolling the virtues of a bigoted French publication which demonizes not only Islam, but all religion. Muslims are pretty much Public Enemy Number One. If you're a Muslim, then you're really not welcome here. Sad, but true.
I really don't think she made assumptions about Muslims, though. She simply made assumptions about her constituents. She's not a diplomat, she's a politician. She has figured out what it takes to get elected, and will ride it to get re-elected. Apparently in her district that means figuring out who to scapegoat. My guess is that this doesn't distinguish her from the other 434 other members of congress. Note that most of the visitors were children. This is a pretty realistic civics lesson for them, probably more brutally honest than their teachers had anticipated.