What did she mean by this?
If you scroll up on the page there's a video of HRC saying it herself. Read between the lines.
Ding ding ding! My bet is that she's worried her remaining cronies in the government won't fight hard enough. POTUS' visit to NK won't just be a milestone in world peace, it'll be a nail in the deep state's coffin if all goes well. They'll be inclined to sabotage it any way they can, by any and all means.