The Office of Special Counsel, which among other things enforces Hatch Act political activities restrictions against federal employees, has issued guidance on post-election activities in the workplace.
OSC noted that the law affects activities on behalf of partisan "candidates" and "typically, a candidate is thought to seek election to an office up until the point at which his or her election to that office is determined.
Generally, candidates are elected to office through direct popular vote, but for the offices of President and Vice President, the actual election takes place through the Electoral College. That means the both presidential tickets remain "candidates” until January 6.
However, activities after votes are cast typically do not affect the results of the election, and therefore "activities like wearing campaign t-shirts or displaying candidate pictures do not constitute political activity, and the Hatch Act does not prohibit a federal employee from engaging in such activities, even while on duty or in the federal workplace.”
It added that Hatch Act restrictions apply at all times to advocating for a party, however. "Even after Election Day, the Hatch Act still prohibits federal employees, while they are on duty or in the federal workplace, from wearing or displaying items that show support for or opposition to a political party or partisan political group. For example, a federal employee can never wear or display a political party t-shirt or similar item in the federal workplace,” it said.
The guidance is here: http://www.osc.gov/documents/hatchact/federal/Wearing%20or%20Displaying%20Partisan%20Items%20in%20the%20Federal%20Workplace%20After%20Election%20Day.pdf
