I think the severability point I raised last week is also important: that is, one can hold that the ban as applied to foreign principals (and particularly foreign governments) is constitutional even if the application to other foreign nationals could be overbroad under First Amendment analysis: See particularly Part IV.B of this Dick Fallon analysis. When there is an easy linguistic way to sever a portion of a statute, that should be done over striking down the entire statute as substantially overbroad.