I saw something the other day and I didn't believe it was true. So, I went and looked it up, and matter of fact it was 100% true.
The last 6 elected Republican Presidents, all the way back to Eisenhower, the Democrat controlled House of Representatives have introduced Articles of Impeachment against and started impeachment proceedings/investigations. Only Ford was "spared" but he wasn't elected, he was Nixon's VP and only in office like 1.5 years.
Sounds like the Democrats just don't like it when their lost the POTUS elections to me.