both sides of the isle like it when Fed laws (or SCOTUS) fall on the side of want they want, and both sides hate it when Fed law falls on the side against what they want. 
I'm sure that Tulsi would NOT want SCOTUS Roe v Wade decision to no longer apply nationally, but yet she wants Fed law to not apply nationally on pot (or, she would ultimately have Fed law change to her view).

'States' Rights' when they disagree with the Fed, and 'Fed Rulez!' when it coincides with their position.

Subject change:
Most posters so far cite Tulsi's common sense.
Really?
Pot use is common sense but cigar use (second hand smoke) is not? Will pot be subject to same second hand smoke laws?
Pot use is okay, but abortion is too? Where's the common sense in that?