Easy.
Obama had already made a well known promise to the Brady Bunch (Brady Anti Gun group) that he had plans to do what he could to help advance their agenda.
This whole thing was orchestrated in order to create a problem supposedly originating in America and American gun suppliers,
which would then be a pretext Obama could point to in order to pass more anti-gun legislation, and essentially re-instate the Brady Assault weapons ban law. Probably even more stricter as he’d have a phony “crisis” he could exploit.
So he created this problem by having the government acquire guns and let them be trafficked to criminals in Mexico, so that he could say “Here’s the problem, it’s originating in the US, and we need to clamp down on gun rights to fix it.”
And it would have been far harsher than the original Brady bill/Assault weapons bans. Look what his solution was for the 10% of people who didn’t have health care. You are damn certain it would be worse.
It is treason because he was scheming against his fellow US citizens to deny them their constitutional rights.
It is also a violation of his oath to defend the Constitution. He was hoping to severely limit if not eliminate citizens’ 2nd Amendment rights.
It may have had a chance of working if that one US border partrol agent hadn’t been murdered by a gun the DOJ allowed to be trafficked to Mexico to exacerbate the problem THEY were creating to provide them a “gun crisis” that they would then claim required them to strip the 2nd Amendment away and basically give Mrs. Brady the big O she’s been waiting for all these years.