Original sentence: Historically, systematic ideology has been unable to produce a  falsifiable causal model for what it is that influences some people and not others to gravitate towards a particular ideology
Edited sentence: If some can do it but not others, systematic ideology has yet to coherently articulate why.More precisely, what it is that influences.Systematic ideology itself was rather hampered by the fact that even if the ideological series it posits is a historically accurate one (which is highly contentious in itself), it has always been unable to adequately explain why this should be so.some people and not others to gravitate through the series towards an ideology such as that supposedly represented by the Socialist Party