With all due respect to Herbert Aptheker (whose book cited above is wonderful, as are his _The Colonial Era_ & _The American Revolution_) and to you Charles, I think you both overstate the case. To say the framers recognized that need for change may arise is one thing (and no small thing given historical context) but there was no consensus about that matter among framers. If memory serves, one of reasons (in addition to absence of bill of rights) George Mason refused to sign document was that he supported 'easy' amending process to counter what he believed would be instances of congressional abuse of power. In other words, he didn't perceive amending process in terms of expected changes to be made over time. In characteristic fashion, Madison's view is a 'balancing act' in that he thought amendment process convention adopted would 'guard equally against that extreme facility, which would render the Constitution too mutable; and that extreme difficulty, which might perpetuate its discovered faults.' Federalist #43). History of amending process raises questions about Madison's moderated claims.
1-10 (Bill of Rights) were concession to anti-federalists in order to secure ratification.
13-15 (post-civil war civil rights) were necessary to alter fundamental law to deal with political consequences of conflict (of course, 14 & 15 were circumvented for almost a century following end of Reconstruction).
16 concerns itself strictly with establishing power of Congress to enact income tax. While such legislation quickly followed, Congress can abolish it (and may yet do so). Moreover, the only original feature of New Deal tax policy was to burden wage-earners who had not previously been subjected to income taxes (and they have borne increasing burden ever since as progressivity has been reduced).
17 (direct election of senators) rounded out change that had long been underway as voters in more than 50% of states had already gained right to indicate preference for senators and state legislatures generally followed their lead.
19 culminated struggle (sort of) that began seventy years earlier in 'granting' women voting rights that 31 states already recognized (at least partially, only about half had granted full suffrage) but it did not affect laws dealing with ownership of property, jury service, marriage & divorce, labor regulations and other women's rights issues of that day (and this one too, in some cases.).
24 (anti-poll tax) only applied to federal elections; five states still levied such tax when amendment was submitted in early 1960s and amendment was rendered superfluous by 1966 Supreme Court decision in *Harper v Virginia Board of Elections* in which states were precluded from imposing poll tax as requirement to vote in any election under equal protection clause of 14. (btw: Senate sponsor of #24 was Spessard Holland who had been in state legislature in 1930s when Florida eliminated poll tax... abolition in Florida had been no indication that racial bigotry was softening, rather state legislators were concerned that opposition interest groups could purchase poll tax receipts in efforts to defeat them. As for Holland, he voted against every single civil rights bill introduced during his four terms in US Senate).
26 (18 yr. old voting rights) was attempt to channel and contain political activity of late 1960s & early 1970s by 'liberal' Dems who thought they would benefit electorally.
ERA defeat indicates how amending process can frustrate wishes of majority as it was designed to do. Of course, many constitutuonal scholars - conservative about and protective of the document - think it is fortunate that the constitution has not been amended more frequently and become laden with prohibitions and complications (as state constitutions tend to be) making governing difficulty. Which is where all that 'living constitution' and 'open texture' interpretability stuff enters the picture. Michael Hoover