She's anti-war.
She believes that there's a military-industrial complex that is unduly incented to promote war.
And then that ultimate sin: she visited, in-person, a secular dictator in the middle-east who was accused of committing genocide. So did American news channel anchors. As a Congressperson (or maybe ex-Congressperson) who had served in active duty in the US military, she had every right to visit and talk to the guy. Build bridges and all that.
It completely baffles me how everyone accuses her of being Putin's agent.
If she's Putin's agent, then produce the evidence and arrest her!
Sorry. I just watched a video on YT which shows the timeline of when the mainstream (media and politicians) turned against her: as soon as she came out as being anti-war.
(Note: the secular dictator was removed with help from the west, and Syria is now run by a leader of ISIS. Are you happier now?)