Correct Jay, "“If Assad didn’t do it, who had the capacity and the motive to do so?” 
Tulsi thought maybe the tooth fairy or it could be the Easter Bunny, she wasn't sure.
The only ones with SARIN GAS, Tulsi, was Assad, and Russia.  The rebels fighting Assad have no capacity to produce such a thing.  Just silliness on her part.
Tulsi "Talks too Much" Gabbard has no choice but to stick to her story about how good Assad is for Syria, she's all in.