Here's an ArsTechnica article on climate change[1] where the very first comment advocates the murder of those who disagree with the liberal position. It has a positive score and many others in the thread defend it.
Liberals can dish it out too, and moderators let them get away with it.
[1] http://arstechnica.com/science/2016/05/climate-hustle-wants-...
He was claiming the Mexican government was purposefully or tacitly sending their problems across the border.
You can disagree with this claim, but don't misconstrue what his message was.
He's also cited this article[0] in reference to the point he's trying to make.
http://fusion.net/story/17321/is-rape-the-price-to-pay-for-m...
One side of the spectrum goes out of their way to spew hate and abuse and incite violence. The other preaches tolerance and respect. You can't really play the "there are two sides therefore the two sides are equivalent just opposed" game here, I think even if you still could manage to do it pre-Trump, Trump killed it by choosing to be objectively worse by all measurements and accounts.
I've yet to meet the democratic nominee who refers to an entire ethnic group as "rapists and murderers".
Maybe twitter removes a lot more posts from the right because those posts are actually racist.