Semites are a subgroup of Caucassoid. So yes, they are caucasian.
For anything non-medical, however, race doesn't matter in the slightest. And even for medical purposes, the differences are minimal. So why would we even care?
Admittedly, I love throwing it in white supremacist's faces every time... 'Hey, you know those really dark-skinned Indian people? Yeah, they're just as 'white' as you are.' It's hilarious.