Kerry O'Grady, special agent in charge of the Denver field, wrote on Facebook: "I would take jail time over a bullet or an endorsement for what I believe to be disaster for this country."
Her comments came after the now infamous leaked audio of Trump talking to Access Hollywood host Billy Bush in 2004 about grabbing women by their genitals.
She ended the post by saying “Hatch Act be damned,” a reference to the 1939 law that promotes fairness in the workplace and nonpartisanship inside the executive branch of government.
"The agency is taking quick and appropriate action," the Secret Service said in a statement.
O'Grady, who has worked for the government for 23 years, made the remark in October.
Many have called for her to be fired from the agency.
Following the backlash, O'Grady told the Washington Examiner that she acted purely out of emotion.
She added that she is proud of the job the Secret Service does and what it stands for.
“I... support the institutions and pillars of our republic established by the very same document that allows my free expression," she told the magazine.
However, O'Grady later deleted the post a few days after it was published.