Trump is almost certainly anti-union himself given he has been an employer most of his life but his comment is not anti-union ideology. If it were he would not be careful about which segment of the union he's criticizing and he would not have positive things to say about their members.

I'm not disputing that at all, I'm just saying that that his statement doesn't demonstrate a pervasiveness of anti-union ideology. In fact it's showing some weariness of coming out too strongly against unions because of popular support for them. Such popular support wouldn't exist if anti-union ideology was widely accepted.