Messing, along with Eric McCormack, Megan Mullally and Sean Hayes, appeared in a video in which characters in the show tried to convince Hayes' Jack McFarland, who is undecided, to vote for either Donald Trump or Hillary Clinton in the 2016 presidential election.
While McCormack's Will Truman and Messing's Grace Adler are supporters of Clinton, Karen Walker, played by Mullally, is firmly in the Trump camp. At the video's end, McFarland decides to vote for Clinton, announcing "I'm with her" because Katy Perry is too.
Messing, 48, said Sunday that the message wasn't to vote for Clinton.
Responding to a tweet claiming that the video supported Clinton, Messing wrote: "No/ it was for #VoteHoney. Jake wasn't going to vote. Karen was for Trump, W&G were for HRC. Msg was you HAVE to vote. Sitting out is not ok."
Messing also said the "Will & Grace" reunion was not a Clinton endorsement in an interview with the Washington Post.
"Votes are the great equalizer," Messing told the Post. "It doesn’t matter if you’re wealthy, it doesn’t matter what color your skin is, or what religion you are, every vote is weighted equally and it is our greatest privilege as Americans."
"Will & Grace" went off the air in 2006.