Republicans should have been better prepared. While it might have made sense to read the Constitution as currently amended (thus omitting the 3/5 clause, etc.), this would also be a good time to play offense on these clauses. Rush today distorted the issue by calling the anti-3/5 clausers "abolitionists"--the liberals of the time. But maybe I missed his irony.
Republicans (or the portion of them that believes in the fundamental documents) should read from as well the Declaration, the Federalist (the whole thing, perhaps on the anniversaries of their original publication), and the great speeches of Washington and Lincoln. The ridicule from the Democrats, the NY Times, and E.J. Dionne would be sufficient to make conservatives' point, but it gives conservatives on the Hill, in the think-tanks, and on blogsites such as this a chance to expand the public debate and understanding about our fundamental legal and political documents.
Conservatives have exposed and could disarm the liberal progressives, because of course the left originated in Woodrow Wilson's denunciation of the Declaration's natural rights and the Constitution based on them. This 18th century understanding should be brought up to date, Wilson contended, by 20th century evolutionary biology, thus leaving our rights in perpetual flux. And, as FDR declared, Wilson was the Democrats' "commander-in-chief." And so he remains.