Like what?
Did he steal children?
Did he collude with the Russians?
Did he need people to steal shit so he wouldn't see it?
He had numerous campaign & administration people indicted?
He put his relatives in important positions in the White House?
He trade a "one china" policy for a trademark in China?
For one, his blatant lies about Obamacare and the government takeover of the health care system.
For two, his support of Islamists. Nearly every ME policy he installed supported radical Islam, and his position regarding the replacement of Mubarak with Morsi and the Muslim Brotherhood in Egypt could not have been more damning.
That's just two off the top of my head.