Why does it seem, IMHO, that the left loves to go after political commentators or viners who state their opinions on various topics as liars ?  Seems to me that if I'm not stating facts and backing them up with undeniable evidence, I'm sharing my opinion.  Is the left unable to see the difference between the two or is it just the same hypocrisy we're used to seeing?

Just because you don't like a differing opinion, does that give you the right to call someone a liar ?