Fun fact, in China, conservatism tend to be related to old-school, Mao-era communism, which is probably considered far-far-left extremists in the free world.
The extreme sides actually join together around the back.
Just the reasoning that tends to get a bit muddy - for race/country/flag/god/people. I think the line tends to be when somebody starts mentioning 'the enemy' - and points to some formerly-considered-random guy nearby.