The 14th does not speak to being convicted. For the civil But Trump will surely bring that up.How can a candidate be disqualified before he is actually convicted of the said disqualifying crime ? Trump has not been convicted. If the situation changes before or during the hearing, that is another matter.
Section 3 in its entirety says this (I've highlighted the point in question) which is did Trump give "comfort" to the Jan 6th insurrectionists by his actions and his lack of actions.
Section 3. 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 enemies thereof. But Congress may by a vote of two-thirds of each House, remove such disability.