Constitutional Law Professors Josh Blackman and Seth Barrett Tillman have published a scholarly paper that argues that the 14th amendment, section 3, does not apply to presidents or to candidates for president. Use this link to see the paper. The title is “Sweeping and forcing the President Into Section 3.”
Section 3 says, “No person shall be a Senator or Representative in Congress, or elector of President and Vice President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enmies thereof.”
Among other points, the article says that common word usage in the 19th century makes it clear that “any office” refers to appointed positions, not elected positions. Thanks to ElectionLawBlog for the link.
At Reason, Steven Calabresi summarizes the points in the article and says he agrees.