There are multiple reports and videos of crowds at his rallies chanting "Kill the bitch, "Hang the bitch", and "Lock her up". Trump knew this and condoned the behaviour. He has actively singled out members of the "corrupt media".
I can respect political differences but this is not normal behaviour for a healthy democracy. It's playing with fire - a fire that may burn out quickly, a fire that may smoulder in the background, or a fire that could burn the whole place down. I'm NOT saying Trump is going to start locking people up (I think he is a populist who said what people wanted to hear) but let's not pretend that the concerns people have are only because of his crude comments about women and minorities.
As I said, it's not about the normal left vs right ideology - Obama and Bush both supported policies that greatly concern me (mass surveillance, drone strikes against US citizens without trial etc). But neither Bush or Obama used this type of rhetoric about their political opponents.