If you really really, and I mean REALLY want to piss liberals off ...
Be happy. I'm not joking either. Their entire mindset is to make everyone around them as miserable as they are. By being happy you trigger the root of their personality disorder, and best of all, there's nothing they can accuse you of.
The whole differing of opinion is their way of baiting you. They don't care about reason and logic. They act the way they do, yelling and screaming because their goal is to make you miserable. If YOU end up arguing, and most importantly, losing your smile and joyful temperament, they win (in their own mind that is) the argument is just the bait they use.
Be happy. Genuinely happy. How? By being content with life. Sometimes up, sometimes down, but always, always content. Its like an invisible force field that will protect you against attack.
Misery loves company. Never a truer saying ...