I felt the same about Hillary
This says more about you than about Sec Clinton.
Democrats have consistently nominated people who are slightly to the left i.e. Judge Garland as an example, so why are you afraid of them?
The typical conservative talking point is any Trump nomination is mainstream American. Sorry but not even close. His potential nominations are all mainstream hard right ideologues. Democrats will never vote for extremists.
Dems will vote for someone slightly to the right, I guarantee it.