A copyright is a right to intellectual property conferred by federal law in accordance whith the Constitution, which specifically gives Congress the power to legislate in that area.
On the other hand, there is no collective "voting public's right to be fully aware of the views of a candidate for President of the US." One cannot sue a candidate for any office on that basis unless the claim is that the candidate has violated some law requiring him or her to fully disclose his or her views. To the best of my knowledge, there is no such broad law and never has been, nor would it be practical to enact one.
So there really is no conflict at all. The copyright holder has the copyright, and anyone who uses the copyrighted material without consent from the copyright holder and in other than a manner consistent with the Supreme Court's "fair use" doctrine opens himself to a possible copyright infringement suit.
You wrote:
there is no collective “voting public’s right to be fully aware of the views of a candidate for President of the US.”
Sure there is:
“Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.” Amendment 1, US COnstitution
That right, as relates to the coming elections, is of higher value than any alleged claim to copyright over this document. No rights are absolute.