The FEC and a number of states have weighed-in on public service announcements featuring officeholders/candidates.  Minnesota’s Campaign Finance and and Public Disclosure Board opines in its advisory opinion 394.   This seems to be a familiar sentiment:

The Board recognizes that any positive public exposure may have some effect on an individual’s chance of being elected. However, this possible collateral effect under the facts presented is not sufficient bring the productions within the scope of speech that is considered to be for the purpose of influencing the nomination or election of a candidate.