On Monday, Trump will head to South Carolina to support McMaster at a political fundraiser, which is expected to provide cash for McMaster's gubernatorial campaign, in Greenville.
During the 2016 presidential election, McMaster became the state's first elected official to endorse Trump's bid for the presidency. He's steadfastly stood by the president since he took office in January, a move that experts say could benefit him in the upcoming race.
"Certainly Trump has a strong following in South Carolina, stronger than other parts of the country," Professor Danielle Vinson of Furman University said.
Several groups plan to protest the event, including activists from across the state.
Demonstrators will oppose Trump at nearby Greenville's Falls Park, and will begin an hour before Trump's scheduled arrival.
Tickets for the event are selling for $250 and there will also be a VIP reception for or corporate donors and individuals who are making large contributions to McMaster's campaign.
That event will start at 6:30 p.m. EDT.