I know they will if you land at your first destination in the US and are catching a connecting flight - they will run you through security a second time before

I know they will if you land at your first destination in the US and are catching a connecting flight - they will run you through security a second time before letting you into the secure area of the airport where you might board another aircraft - but that's only if you are connecting. Then again - my experience travelling says this has a lot more to do with airport layout dictating security procedure more than anything else - some airports seem to change policies every time I fly - one time I have to collect my bags, the next I don't, the next I can actually just catch an international connection, the next time I can't without getting my bags, etc (all through the same airport through the past few years)