Hillary Clinton was set to speak in Washington, D.C. at the 2019 Fortune Most Powerful Women Summit, but it appears that her plans have changed.

Clinton cited a scheduling conflict as her reasoning for the drop out. However, a source close to the Clinton’s told Slate that the decision to cancel was made because Kirstjen Nielsen, the former secretary of homeland security, is also scheduled to speak at the event.

Coincidentally, one of the other speakers attending the summit is 2020 Democratic presidential candidate Tulsi Gabbard.

This news broke after Clinton and Gabbard’s heated battle on Friday. Clinton suggested that Gabbard was being groomed by a foreign government for her presidential bid, referring to her as a “favorite of the Russians.” (RELATED: Van Jones: Hillary Clinton Is ‘Playing A Very Dangerous Game’ With Gabbard Criticism)

Following Hillary’s comments, Tulsi unleashed on Twitter, calling Clinton “the embodiment of corruption and personification of the rot that has sickened the Democratic Party for so long.”

In her statement, Gabbard also urged the former first lady to join the 2020 race. (RELATED: ‘I Stand Against Everything She Represents’: Tulsi Gabbard Deconstructs Hillary Clinton In ‘Tucker Carlson Tonight’ Interview)