I think your first paragraph is completely irrelevant.
I think sober driving with marijuana in your car creates no more risk than if you didn't have it. Unless of course the transporation of the marijuana is the purpose of your trip in which case increased risk arises due to your being on the road. Other than that, transporting marijuana could actually reduce risk to yourself and those around you by encouraging you to drive more carefully and therefore less likely to get into a collision or pulled over for some other violation.
That's what I think.
Also, if you're only transporting marijuana and not driving impaired, you shouldn't have anything to worry about if you're smart about it. Keep it hidden in the car, not on your person. Don't put it in your glovebox or some other place where it might inadvertently be seen. And most importantly, KNOW YOUR 4th AMENDMENT RIGHTS AND HOW TO STAND UP FOR THEM.
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