Remember the Obama birth certificate thing? It was actually supporters of the Clinton campaign that first surfaced those questions in 2008 when she was trailing to Obama. It Trump who kept going on that issue, long after everybody else had dropped it. This produced a big win for Obama after the real certificate came out. Trump is friends with the Clintons; they attended his wedding in 2005.
If you’re disgusted by Trump’s behavior, you should consider who keeps his company.
EDIT: and then there’s this article published a month later saying that Trump talked with Bill Clinton about whether he should run.