This is true. Right-wingers & left-wingers are both extreme in their sociocultural, psychosocial, & sociopolitical beliefs. Both of them are of the same psychological makeup but at opposing ends of the spectrum. Both of them can be classified as fanatical, it is all or nothing for them. Neither of them are moderate in their particular beliefs. They can be classified as do or die. Furthermore, they are HIGHLY INTOLERANT of those who have differing/opposing belief system. They are even highly dismissive of those in their faction whose subset of beliefs vary slightly from theirs.