You say "you have to", but what actual reason to believe this do you have besides that some other condescending prick told you so? When I look at historical liberation movements (and I can't say I know all of them, granted), they never got by on entryism and, at their most normative, still conformed to Marx's advice of establishing an independent political party, though often they were much more underground than that, often branded terrorists, etc. They certainly didn't fucking campaign for their own opposition like you're supposedly doing now (though in reality I don't think you really are in opposition to Harris) and generating more of a popular mandate for the establishment.