Former two-term South Carolina Gov. Mark Sanford announced on Sunday that he will run a primary challenge for the 2020 Republican presidential nomination against Donald Trump.

Sanford faces an uphill battle to win the nomination. Given Trump’s approval amongst Republican voters – consistently around 90 percent – any challenge for his place as the GOP candidate is considered a long shot. Sanford joins the likes of former Massachusetts Gov. Bill Weld and former Illinois Rep. Joe Walsh in challenging Trump.

“I had planned to announce that back home this week. We had a hurricane come visit us on the coast of South Carolina so that sort of disrupted plans on that front,” Sanford said. “But I am here to tell you now, that I am going to get in.”

Sanford, 59, enters the race with some name recognition. He served two terms as governor, winning both elections by a solid margin. He also has some credentials within the Tea Party movement, having been considered a top ally of former Rep. Ron Paul.

Trump’s reelection campaign offered a dismissive one-word response to Sanford’s announcement: “Irrelevant,” spokesman Tim Murtaugh said, according to CNN.

“I think we need to have a conversation on what it means to be a Republican,” Sanford explained when asked why he was running, further elaborating that he believes the party has lost its way. Sanford had told CNN in July that “debt, deficit, and government spending” would be focal points of his campaign should he run, as he believed they were issues not being discussed enough in Washington.

As a vocal critic of Trump, Sanford has faced pushback from a Republican base overwhelmingly loyal to the president. Last year, Sanford lost in the primary race for South Carolina’s 1st Congressional District.

“I just got through watching two Democratic debates that offered little more than a long laundry list of new political promises that we can't afford,” Sanford said. “I listen to the President, who rules out action on the very things that drive our debt and spending.”

Sanford has faced controversy as governor, drawing national headlines in 2009 when an unexplained absence later revealed that he was having an affair. He would ultimately survive talk of impeachment and finish his term.

Sanford's presence in a growing Republican field comes amid some talk of Republicans canceling the 2020 presidential primaries altogether to support Trump. The Republican Party in South Carolina has already moved to cancel their state’s primaries, and the Kansas branch of the party has decided not to hold a caucus for the 2020 election.

South Carolina Governor Mark Sanford addresses the media at a news conference at the State House in Columbia
South Carolina Governor Mark Sanford addresses the media at a news conference at the State House in Columbia, South Carolina September 10, 2009. REUTERS/Joshua Drake