Like many documents before and after it the Communist Manifesto was intended for the audience at the time. Much like other political documents the communist manifesto was a product of it's time and made it's appeal to people of the lower class in 1848 provoking them by using problems of the time to get the working classes attention. Along with pointing out the problems with society the Communist Manifesto describes the war between the poor and rich offering the poor an alternative to their current situation. Since times change the issues that the Communist Manifesto used to rally support for it's cause have long since vanished, with this change the Communist Manifesto has lost some of it's relevance.
Now that the gap between the rich and poor has shrunk and with the creation of the middle class the Communist Manifesto has lost a considerable amount of relativity this loss has resulted in a massive loss of support this has made the Communist Manifesto a radical and unpopular document. The Communist Manifesto has fallen short on many issues by not describing how to resolve future problems. This is one of the documents many deficiencies, this deficiency has resulted in the documents inability to change over time resulting in a radical document that is bound in it's quest for the "Abolition of private property" (Marx, Engels) without being subject to modern change the Communist Manifesto like many documents before it is doomed to fail as a political document.