I've had several occasions when I've brought up politics with someone I thought I knew well and started getting a lecture about the need for a proletarian revolt to seize the means of production, which is pretty shocking to me because it's the 21st century. It's a good sign to never talk to said person again.
Is it now?
I'd certainly not find such a person more annoying than 90% of the political discussions I'm forced to overhear. Certainly preferrable to the sort of non-thinking, instinctive 'latte' left you find a lot in certain University departments' student corps.