"Mark Sanford will be a consistent vote to get spending under control, pass a balanced budget amendment to the Constitution, repeal and replace ObamaCare, and make the tax code fairer and simpler for all Americans," FreedomWorks PAC President Matt Kibbe said in a statement. "FreedomWorks PAC activists across the District support Mark Sanford and we will be taking action in this final week to make sure Mark Sanford represents District 1 taxpayers in Washington."

The organization is the latest to give some belated support to Sanford, whose election is next Tuesday — Sen. Rand PaulRand PaulTrump: 'No doubt' we'll make a deal on healthcare Overnight Defense: General says US strike probably led to civilian deaths | Tillerson to push NATO on spending | Trump taps F-35 chief Senate backs Montenegro's NATO membership MORE (R-Ky.) also endorsed him on Tuesday, and South Carolina Gov. Nikki Haley (R) is headlining a fundraiser for him on Wednesday.

FreedomWorks has spent approximately $7,000 so far on yard signs for him, a tiny investment for what's turned into an expensive race, and plans to host a get-out-the-vote rally this Saturday. National Democratic groups are on pace to spend more than $900,000 combined against him.