The same party as the president in control of congress has never impeached one. Andrew Johnson was a Democrat who ran together with Abraham Lincoln on a National Union ticket and was impeached by the Radical Republicans. Bill Clinton was a Democrat impeached by the Republicans. Dick Nixon was a Republican threatened with impeachment by a majority Democratic congress, so he resigned. Here endeth the lesson.
Yes, thank’s for reminding us it wasn’t the Republican Party that gave us Andrew Johnson. Probably should have stayed Republican and kept Hamlin. Heck, Benjamin Beast Butler might have been better. Or not.