If Trump didn't act so weird to Russia after they tried to rig our election making him president there wouldn't of been an investigation.
So many strange acts by Trump here are just a few
Saying Russia if your listening release Hilary Clintons Emails.
Going on and on about Wiki Links.
Trump tower meeting between his son and Russian agents ,and then making up lies about it.
Trying to build a Trump Tower in Russia almost right up to the day of the election and keeping it a secret then later lying about it after he became president
Not wanting to sanction Russia for interfering in our elections.
Firing James Comey then the next day saying it was because of this Russia Thing.
There still weird things happening every time Putin and Trump meets like not making records of there meetings.
So if they thought Trump needed to be investigated you should be able to see why.