What did President Nixon do wrong to almost get him impeached?

he had the bad guys he didn't trust wire tapped trying to get evidence on them. there was more but that was watergate. You should see the many cornell profs leaving wash to NY when things got hot.Nixon started getting the attitude more or less like a dictator trying to get his way without going through the proper channels,as they are getting away with a lot of that today.Nixon also had a lot of good points.I probably would be tempted to do the same to expose evil corruption.The whole story is probably on the web.