Dave Armstrong has posted a series of "25 Short Arguments on the Difficulties of Perspicuity (Clearness of Scripture for Salvation)" (link) from his book "501 Biblical Arguments Against Sola Scriptura: Is the Bible the Only Infallible Authority?" I can see that his list of arguments has received nearly a thousand views, so perhaps it makes sense to provide a response to each of these. The arguments themselves are not long - individually they are no more than smudges that aim to obscure Scripture's clarity. This is number 7/25 of my wiping away of the smudges.
7. The U.S. Constitution might be regarded as true and wonderful and sufficient, etc. But the fact remains that this abstract belief only lasts undisturbed as long as the first instance of case law in which two parties claim divergent interpretations of the Constitution. It's the same with Protestants.
The major error in this argument is that it assumes a bogus standard for sufficiency. The minor error is that the analogy to the U.S. Constitution is false.
For the Scriptures to be wonderful and sufficient, there is no requirement that they eliminate every disagreement about themselves. Such a false standard for sufficiency is strange - Dave's own church includes plenty of internal disagreement over their own standards. We don't claim that the Scripture prevents people from disagreeing - and surely disagreement is an invalid standard of measurement of the sufficiency of any standard.
As for the U.S. Constitution - it is not divinely inspired. The Holy Spirit doesn't promise to lead Americans into a proper understanding of the Constitution, but does promise to lead believers into the truth:
John 16:13 Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.
Likewise there is no American spirit that provides as fruit the analogous equivalent of "goodness and righteousness and truth."
Ephesians 5:9 (For the fruit of the Spirit is in all goodness and righteousness and truth;)
Thus, while the U.S. Constitution may be as clear as men can make it, the Scriptures are a divine production - they are inspired.