No, it does not - any threats against the line of successuion to the presidency are covered under this title.
Also, calling for the assassination of public officials during time of war is sedition and possibly treason.
Please learn the law before expressing your "opinion".
I read the applicable law - unless there is an expansion beyond a literal reading of 18 USC 871 it only applies to those directly in line. This is not an opinion, but no plain reading of 18 USC 871 allows it to apply to further down the line members of the succession unless they are actually next in line. Look at this:
upon the President of the United States, the President-elect, the Vice President or other officer next in the order of succession to the office of President of the United States, or the Vice President-elect That does not include the individual who is five steps away from the Presidency. But you may know of a court case that expands this further - just the code does not. 18 USC 115 may apply, however. Is the sedition limited to times of declared war? Not that I am questioning, but I would think an actual declaration may be necessary.