Not enough people understand or want to admit that's what they are doing.
Combined with that is the mistaken notion that there is no difference between the two.
They mistake not as big a difference as they'd like with no difference.
Also, the ultra-cynical and nihilistic mind set and worldview instilled by the liberal influence that permeates everything is at play in causing people to come to the "they're all the same" attitude.
Liberal thought can affect people who do not buy in to the liberal political agenda in negative ways.