@hawkeye10,
Quote:. . . no one can go back and change history either, so it is a continuing
threat as well.
True. And it may be that Obama's history is also a reason for threats.
The writer states that among other reasons, race is "prime". Now what he/she
means by "prime", I'm not sure. I suspect the writer is saying that those who
have made threats that include racial references are more virulent than the
others. But, of course, there's no way for us to know. We haven't heard or
read all the threats ourselves.