'Centrists' don't help much either because they too hold the left to a higher standard than the right and always seem to be looking for any excuse to whip out the ol' "so much for the tolerant left" so that they can feel better about themselves when they vote for who they really wanted to vote for anyway.
People on the right can say in plain English "I want to dismantle women's rights and put all gay people into camps" and the 'centrist' will be like "hmmm yes that seems like a valid political opinion". But the moment someone on the left drops the high road shit for once and bites back, the 'centrist', clutching pearls is like "See? This is why I'm supporting the bigots that hate everyone, because you SWORE and that's unacceptable!"