If the tape that Chris Thieneman provided for WHAS in which Mitch McConnell aide Larry Cox says he was calling Thieneman from his office is true, it appears that Mitch McConnell may have a problem
Campaign work by congressional staff. Subject to the restriction on handling federal campaign funds (see discussion below on “political fund designees”), Senate employees are free to engage in campaign activity on their own, as volunteers or for pay, provided they do not do so in congressional offices or otherwise use official resources and provided they do not neglect their official duties.
It is also important to note that this prohibition also appears to pertain to actions
on behalf of campaigns beside their own employer, such as the Congressional campaign of Anne Northup:
Members and staff should be aware that the general prohibition against campaign or political use of official resources applies not only to any Member campaign for re-election, but rather to any campaign or political undertaking. Thus the prohibition applies to, for example, campaigns for the Presidency, the U.S. Senate, or a state or local office, and it applies to such campaigns whether the Member is a candidate or is merely seeking to support or assist (or to oppose) a candidate in such a campaign.